The Development of Sympathetic Innervation and the Functional State of the Cardiovascular System in Newborn Dogs

1975 ◽  
Vol 53 (5) ◽  
pp. 763-776 ◽  
Author(s):  
Pierre Gauthier ◽  
Réginald A. Nadeau ◽  
Jacques de Champlain
Keyword(s):  
Blood Pressure ◽  
Salivary Glands ◽  
Sympathetic Innervation ◽  
Cardiovascular Responses ◽  
Systemic Blood Pressure ◽  
Lower Blood ◽  
Norepinephrine Content ◽  
The Right ◽  
Newborn Animals ◽  
Full Maturity

The present study in dogs indicates that the peripheral sympathetic fibers develop mostly after birth and reach a full maturity at about 2 months of life. The norepinephrine content of the heart, spleen, intestine, salivary glands, and adrenal glands increased from birth to 56 days of age. In contrast, the content of the stellate ganglia decreased during this period. In most of the organs studied, the uptake of [3H] norepinephrine developed in parallel with the norepinephrine content, except in the right atrium and salivary glands where it was fully developed soon after birth. During development, the systemic blood pressure increased from 40 to 100 mm Hg. Bilateral adrenal vessel clamping failed to induce a fall in blood pressure in growing dogs which indicates that the adrenal medulla or the baroreceptors did not fully compensate for the lack of peripheral sympathetic fibers and for the lower blood pressure in newborn animals. Although cardiac norepinephrine content was still very low in 10-day-old animals, cardiovascular responses to direct and reflex sympathetic stimulation were similar to those observed in 56-day-old animals. These results indicate that the sympathetic nervous system becomes functional before the fibers reach their full maturity.

Respiratory and cardiovascular responses to increased and decreased carotid sinus pressure in sleeping dogs

1995 ◽  
Vol 78 (5) ◽  
pp. 1688-1698 ◽  
Author(s):  
K. W. Saupe ◽  
C. A. Smith ◽  
K. S. Henderson ◽  
J. A. Dempsey
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Eye Movement ◽  
Carotid Sinus ◽  
Minute Ventilation ◽  
Control Level ◽  
Cardiovascular Responses ◽  
Systemic Blood Pressure ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep

The purpose of this study was to determine the effects of changing blood pressure in the carotid sinus (Pcs) on ventilatory output during wakefulness and non-rapid-eye-movement sleep in unanesthetized dogs. Eight dogs were chronically instrumented so that ventilation, heart rate, and blood pressure could be measured while pressure in the isolated carotid sinus was rapidly changed by means of an extracorporeal perfusion circuit. Raising Pcs 35–75 mmHg consistently reduced ventilation 15–40% in a dose-response fashion, with little or no further diminution in minute ventilation as Pcs was further increased > 75 mmHg above control level. This decrease in minute ventilation was immediate, due primarily to a decrease in tidal volume, and was sustained over the 20-s period of elevated Pcs. Increases in Pcs also caused immediate sustained reductions in systemic blood pressure and heart rate, both of which also fell in a dose-dependent fashion. The ventilatory and systemic cardiovascular responses to increased Pcs were the same during wakefulness and non-rapid-eye-movement sleep. Decreasing Pcs 40–80 mmHg caused a sudden carotid chemoreceptor-mediated hyperpnea that was eliminated by hyperoxia. We conclude that increasing Pcs causes a reflex inhibition of ventilation and that this reflex may play a role in sleep-disordered breathing.

Responses of the canine myocardium to stimulation of thoracic cardiac nerves

1977 ◽  
Vol 232 (5) ◽  
pp. H485-H494 ◽  
Author(s):  
J. E. Norris ◽  
W. C. Randall
Keyword(s):  
Blood Pressure ◽  
Systemic Blood Pressure ◽  
Type Ii ◽  
Systemic Blood ◽  
Type Iv ◽  
The Right ◽  
Alpha Chloralose ◽  
Canine Myocardium ◽  
Cardiac Nerves ◽  
Stimulation Of

The thoracic cardiac nerves were stimulated in each of 21 dogs anesthetized with alpha chloralose. Recordings were made of heart rate, blood pressure, and contractile force from all four cardiac chambers. Walton-Brodie strain-gauge arches were sutured to both atria, and to three locations of each ventricle, representing both anterior and posterior surfaces. The functional autonomic components of each nerve were summarized and classified into four basic types. Types I and II were both located medial to the thoracic vagi. These were shown to contain both sympathetic and parasympathetic components traveling to all four chambers of the heart. The sympathetic componnent of the type II nerves produced reflex changes in force of contraction and systemic blood pressure. Nerves classified as types III and IV produced no parasympathetic effect on the heart. These were all located lateral to the thoracic vagi. While the type III nerves carried sympathetic efferent fibers to all four chambers, the type IV nerve carried sympathetic fibers predominantly to the right atrium.

Cardiovascular responses during feeding in newborn lambs

1989 ◽  
Vol 257 (3) ◽  
pp. R568-R573
Author(s):  
B. L. Langille ◽  
S. L. Adamson ◽  
S. A. Jones
Keyword(s):  
Blood Pressure ◽  
Skeletal Muscle ◽  
Gastrointestinal Tract ◽  
Pressor Response ◽  
Sympathetic Innervation ◽  
Cardiovascular Responses ◽  
Bottle Feeding ◽  
Chemical Sympathectomy ◽  
Thyroid Glands ◽  
6 Hydroxydopamine

We examined the cardiovascular responses to bottle feeding in newborn lambs. Feeding induced a persistent rise in blood pressure, from 76.3 +/- 1.9 mmHg to 114 +/- 3.8 mmHg, that lasted for the duration of the feeding episode. This was accompanied by a transient tachycardia that lasted for approximately 10 s at the beginning of each feeding episode. Vasoconstriction of the hindlimb circulation, the gastrointestinal tract, kidneys, and adrenal and thyroid glands contributed to the pressor response, whereas changes in skeletal muscle resistance were not statistically significant. Of tissues assessed, only those actively involved in feeding (tongue and esophagus) vasodilated. Feeding tachycardia was greatly inhibited or abolished by the beta-blocker propranolol but the alpha-blocker phentolamine caused only moderate inhibition of the pressor response. Furthermore, chemical sympathectomy with 6-hydroxydopamine delayed the onset of the pressor response but did not abolish the ultimate rise in pressure. These findings indicate that feeding causes a significant pressor response in newborn lambs that is only partially mediated by sympathetic innervation.

The effect of nimodipine on intracranial pressure

1987 ◽  
Vol 67 (3) ◽  
pp. 387-393 ◽  
Author(s):  
Mark N. Hadley ◽  
Robert F. Spetzler ◽  
Mary S. Fifield ◽  
William D. Bichard ◽  
John A. Hodak
Keyword(s):  
Blood Pressure ◽  
Intracranial Pressure ◽  
Systemic Blood Pressure ◽  
Artery Occlusion ◽  
Content Type ◽  
Arterial Blood ◽  
Increased Risk ◽  
Before And After ◽  
The Right ◽  
Cerebral Artery Occlusion

✓ Nimodipine was administered by intravenous infusion to six male baboons before, during, and after 6 hours of middle cerebral artery occlusion. Intracranial pressure (ICP) and systemic blood pressure were monitored continuously. An epidural balloon was inflated at regular intervals at three levels of arterial CO2 tension (25, 35, and 50 mm Hg) before and after the administration of nimodipine, and volume-pressure curves were generated. In every case, curves generated after intravenous nimodipine infusion were lower and shifted more to the right than the same set of curves generated before nimodipine administration, regardless of the baseline ICP. The reduction in ICP following nimodipine infusion was not due to a reduction in mean arterial blood pressure and was statistically significant at all three levels of pCO2 (p < 0.01). These results suggest that, in the presence of elevated ICP due to cerebral infarction, there is no increased risk of exacerbating intracranial hypertension with the addition of nimodipine.

scholarly journals Intraocular pressure in postmenopausal Nigerian women with and without systemic hypertension

2011 ◽  
Vol 70 (3) ◽  
Author(s):  
J. A. Ebeigbe ◽  
P. N. Ebeigbe ◽  
A. D. A Ighoroje
Keyword(s):  
Blood Pressure ◽  
Intraocular Pressure ◽  
Postmenopausal Women ◽  
Systemic Blood Pressure ◽  
Systemic Hypertension ◽  
Systemic Blood ◽  
Nigerian Women ◽  
The Difference ◽  
Post Menopausal ◽  
The Right

Background: Mean intraocular pressure (IOP) in postmenopausal women has been reported higher than that in menstruating women. Also, intraocular pressure is said to be positively correlated with systemic blood pressure. No previous study in Nigeria has compared intraocular pressure in postmenopausal women with and without systemic hypertension. Purpose: To investigate the effects of menopause on intraocular pressure in subjects with and without high blood pressure. Methods: Normotensive and hypertensive premenopausal and postmenopausal subjects in the   same agerange of 45 to 55 years were studied. Intraocular pressure was measured with the hand-held Kowa applanation tonometer.  Blood pressure was taken in the sitting position at the right upper arm using a manual mercury sphygmomanometer with the right cuff size. The average of two readings was recorded. Results: Mean IOP for premenopausal normotensive women was 14.58 ± 2.56 mmHg whilethat of postmenopausal normotensive women was16.15 ± 1.80 mmHg (p<0.05).  Also, the difference in mean IOP between premenopausal hypertensive (16.58 ± 3.23 mmHg) and postmenopausal hypertensive women (18.24 ± 3.89 mmHg)was statistically significant (p<0.05). A statistically significant and positive correlation was observed between IOP and systemic blood pressure in postmenopausal hypertensive women, p<0.05.Conclusion: Menopause significantly increases intraocular pressure. Mean intraocular pressure of hypertensive postmenopausal women was significantly higher than that of normotensive post-menopausal women, (p<0.05). Knowledge of the normal level of intraocular pressure during various stages of the female reproductive cycle may help during glaucoma screening. (S Afr Optom 2011 70(3) 117-122)

Apnea, tachypnea, and hypotension elicited by cardiac vagal afferents

1979 ◽  
Vol 47 (2) ◽  
pp. 312-318 ◽  
Author(s):  
D. R. Kostreva ◽  
F. A. Hopp ◽  
E. J. Zuperku ◽  
J. P. Kampine
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Initial Rate ◽  
Systemic Blood Pressure ◽  
Left Ventricular ◽  
Vagal Afferents ◽  
Systemic Hypotension ◽  
Stellate Ganglia ◽  
Conduction Velocities ◽  
The Right

The reflex effects of right and left ventricular distension, mediated by vagal afferents, were studied in mongrel dogs anesthetized with halothane or pentobarbital sodium on heart-lung bypass. Diaphragm electromyogram (D-EMG), systemic blood pressure, and left ventricular cardiogram were all measured during ventricular distension. After bilateral section of the stellate ganglia, distension of the left ventricle produced an apnea, or slowing of respiration and systemic hypotension, without a change in heart rate. A reflex decrease in the amplitude of the D-EMG occurred if the initial breathing rate was high; a decrease in frequency of the D-EMG bursts occurred if the initial rate was low. The left ventricular vagal afferents altering respiration had conduction velocities between 22 and 70 m/s, whereas those causing hypotension had conduction velocities less than 22 m/s. Distension of the right ventricle resulted in a significant tachypnea and systemic hypotension without a change in heart rate. The conduction velocities of the right ventricular vagal afferents causing both tachypnea and hypotension were less than 9 m/s. These reflex changes in respiration and blood pressure elicited by both right and left ventricular distension were eliminated with vagotomy.

Cardiovascular Responses to the Intracarotid Injections of Ionic Contrast Media and Iohexol in the Dog

1986 ◽  
Vol 27 (6) ◽  
pp. 729-733 ◽  
Author(s):  
K. Hayakawa ◽  
T. W. Morris ◽  
R. W. Katzberg ◽  
H. W. Fischer
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous System ◽  
Contrast Media ◽  
Vascular Resistance ◽  
Isotonic Saline ◽  
Cardiovascular Responses ◽  
Systemic Blood Pressure ◽  
Ionic Contrast ◽  
S Period

Hypotension and bradycardia are the most significant cardiovascular responses resulting from intracarotid injections of hypertonic contrast media (CM). We have assessed both local and systemic vascular responses to the selective intracarotid injections of ionic and non-ionic CM in twelve pentobarbital anesthetized dogs. Alterations in blood pressure, heart rate, and femoral, renal and carotid blood flows were monitored following right common carotid artery injections of ionic contrast media (282–288 mg I/ml), isotonic saline, and iohexol (300 mg I/ml). Ionic CM led to early (0 to 10 s) decreases in blood pressure, heart rate and femoral vascular resistance. Isotonic saline induced no significant early changes in these same parameters while iohexol caused a decrease in heart rate. Our observations suggest that the early (0 to 10 s) decreases in femoral vascular resistance, heart rate and pressure that occur with the intracarotid injection of hypertonic CM are mediated via the autonomic nervous system and initiated from a site in the carotid circulation. During the 15 to 40 s period when the CM has reached the systemic circulation, iohexol produced smaller effects on systemic blood pressure and peripheral vascular resistances than did the ionic CM. During this 15 to 40 s period there were decreased vascular resistances in the carotid and renal vascular beds that probably result from local effects of the CM, however, the femoral resistance was actually increased. This later increase in femoral resistance probably represents the results of increased sympathetic nervous system activity working to offset the decrease in renal and carotid resistances and thus maintain pressure at baseline values. The vascular resistance changes observed demonstrate a complexity of responses to CM not previously appreciated.

Cardiovascular responses to noxious radiant heat in anesthetized cats

1983 ◽  
Vol 245 (4) ◽  
pp. R576-R580 ◽  
Author(s):  
S. E. Abram ◽  
D. R. Kostreva ◽  
F. A. Hopp ◽  
J. P. Kampine
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Skin Temperature ◽  
Tibial Nerve ◽  
Cardiovascular Responses ◽  
Radiant Heat ◽  
Systemic Blood Pressure ◽  
Nerve Activity ◽  
Hind Footpad ◽  
Somatosympathetic Reflex

The responses of heart rate and blood pressure to noxious radiant heat were studied in seven pentobarbital-anesthetized cats. Afferent activity recorded from the tibial nerve, systemic blood pressure, and heart rate were monitored as skin temperature of the hind footpad was raised to 53 degrees C for 20 s using radiant heat. The averaged tibial afferent nerve activity increased markedly as skin temperature approached 52 degrees C. Within 2-3 s of the onset of increased tibial nerve activity, systolic blood pressure increased an average of 32 mmHg and heart rate increased an average of 16 beats/min in the seven animals that were studied. The results of this study provide evidence for a somatosympathetic reflex that is initiated by cutaneous nociceptors. Under pentobarbital anesthesia, an increase in heart rate and blood pressure appears to be a reliable indicator of nociceptor activation.

scholarly journals The Acute Effect of Hemodialysis on Choroidal Thickness

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Osman Çelikay ◽  
Sinan Çalışkan ◽  
Tolga Biçer ◽  
Naciye Kabataş ◽  
Canan Gürdal
Keyword(s):  
Blood Pressure ◽  
Choroidal Thickness ◽  
Linear Regression Analysis ◽  
Systemic Blood Pressure ◽  
Acute Effect ◽  
Multivariate Linear Regression Analysis ◽  
Before And After ◽  
Patients With Diabetes ◽  
The Right ◽  
Stage Renal Disease

Objective. To determine the effect of hemodialysis (HD) on choroidal thickness (CT).Methods. The right eyes of 41 patients with end-stage renal disease (ESRD) undergoing HD were included. All patients underwent an ophthalmic examination, including CT measurement via optical coherence tomography, intraocular pressure (IOP), blood pressure, and body weight measurement immediately before and after a HD session.Results. Mean subfoveal choroidal thickness (SFCT) after HD decreased significantly from 254.59 ± 84.66 µm to 229.34 ± 77.79 µm(p<0.001). CT at the temporal and nasal regions also decreased significantly after HD (bothp<0.001). IOP changes after HD were insignificant(p=0.958). CT difference was insignificant in patients with diabetes mellitus (DM) and without DM before and after HD, respectively (p=0.285andp=0.707). Stepwise multivariate linear regression analysis showed that diastolic blood pressure was the best fitted factor to explain the changes in CT (r=0.327andp=0.040).  Conclusion. CT was decreased in the patients with ESRD following a HD session. This study suggested that the changes in CT may be related to the changes in systemic blood pressure.

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