The Temperature-Pulse Rate Curve of the Isolated Frog'S Heart (RANA TEMPORARIA)

1951 ◽  
Vol 28 (2) ◽  
pp. 141-164
Author(s):  
C. L. SMITH
Keyword(s):  
Temperature Coefficient ◽  
Pulse Rate ◽  
Anterior Pituitary ◽  
Complex Form ◽  
Type A ◽  
Ringer Solution ◽  
Rate Curve ◽  
Pituitary Hormone ◽  
Temperature Pulse ◽  
Type C

1. The form of the temperature-pulse rate curve of the isolated frog's heart, when perfused with Ringer solution containing adrenaline, has been determined over the range 7-17° C. for monthly samples of frogs over a whole year. Five different types of curve were obtained during this seasonal survey, namely types A, B, C, D and E. Of these types, A and C respectively correspond to the winter and summer temperature- pulse rate curves described by Barcroft & Izquierdo (1931), while the remaining three have not previously been described. Type E, which is a linear relation with a mean temperature coefficient (Q10) of 2.12, has been interpreted as being the least complex form, in which the action of temperature on the pulse-rate is not complicated by the action of other factors. 2. The addition of various extracts of the anterior pituitary gland to the medium perfusing type E hearts led to a disproportionate increase in pulse rate above 10° C, so that the observed temperature coefficient was increased and curves of type B or D were produced. The variation in the response obtained by various pituitary extracts has been attributed to quantitative differences. 3. The typical action of anterior pituitary extract was only obtained when the heart was perfused with Ringer solution containing adrenaline. This phenomenon has been explained by assuming that there is a synergistic action between adrenaline and an anterior pituitary hormone which is inhibited at temperatures below about 10°C. 4. Thyroxine was found to have no action on the type E heart perfused with Ringer containing adrenaline, but if an extract of anterior pituitary were also present, then the type E curve was changed into type C. This is in agreement with the work of Carter (1933). Experiments were also made which showed that previous injection of thyroxine into frogs kept in the cold changed type A (winter) into type C (summer) curves. 5. It was found that adrenaline could either increase, decrease, or have no effect on, the temperature coefficient of the isolated heart. A decrease in the temperature coefficient was only observed in cases where the hearts had been isolated from frogs with active thyroids and has been attributed to the experimental technique employed. The fact that an increase in temperature coefficient may or may not be caused by adrenaline, as well as the fact that type A or C curves have been obtained when hearts were perfused with adrenaline-free Ringer has been attributed to the persistence, in varying degree, of an active sympathetico-mimetic substance in the heart for at least several hours after isolation. 6. It has been shown that the type C temperature-pulse rate curve is the only one which can definitely be attributed to the presence of the thyroid hormone. The seasonal occurrence of this type of curve closely parallels the cycle of thyroid activity described by Sklower (1925) and Meisenheimer (1936).

Sympathomimetic Activity in the Isolated Frog's Heart (Rana Temporaria)

1952 ◽  
Vol 29 (3) ◽  
pp. 337-356
Author(s):  
C. L. SMITH
Keyword(s):  
Ascorbic Acid ◽  
Pulse Rate ◽  
Rana Temporaria ◽  
Liver Extract ◽  
Isolated Heart ◽  
Protective Action ◽  
Time Lag ◽  
Type A ◽  
Rate Curve ◽  
Temperature Pulse

1. It was found that addition of ascorbic acid or an extract of frog's liver to the medium perfusing hearts showing a linear, low Q10, temperature-pulse rate curve (type E) led to an increased frequency response at the higher temperatures. By such treatment curves of types A, B or D were obtained (Smith, 1951). 2. In nearly all cases it was necessary to add adrenaline (1 in 107) to the perfusate to obtain an early response of this nature. In the absence of external adrenaline a similar change was observed after longer treatment with ascorbic acid or liver extract (up to 20 hr.). The possible action of adrenaline in this respect is discussed, and it is suggested that it may afford protection to sympathomimetic substances in the heart tissues. 3. The occurrence of a decreasing acceleration of pulse rate at higher temperatures in certain types of hearts was observed. This phenomenon was reversible on lowering the temperature again, but there was a marked time lag before equilibrium was re-established. When such hearts were treated with ascorbic acid or liver extract, and type A or B curves produced, the direction of this delayed pulse rate change was reversed. The significance of this behaviour in relation to the hypothesis that sympathomimetic substances are synthesized by the isolated heart is discussed. 4. It is suggested that the observed modifications of the type E curve produced by treatment with anterior pituitary extract, liver extract, or ascorbic acid were due to their action in promoting synthesis of adrenergic material by the heart. In the case of ascorbic acid there was evidence for an additional protective action. 5. It was found that treatment of types A or B hearts with ergotoxine and iodoacetic acid caused a definite change of the temperature-pulse rate curve towards the type E form. 6. Temperature-amplitude curves were constructed for numerous hearts of various types, and it was found that distinct forms occurred in correlation with the different types of temperature-pulse rate curves. It has been shown that the frequency and amplitude changes are related in such a way that they can both be attributed to production or inactivation of sympathomimetic substances. 7. The action of thyroxine in modifying the form of the temperature-pulse rate curve is attributed to its protective action on adrenergically active compounds. 8. An analysis of the various forms of temperature-pulse rate curve has been made on the basis of the action of temperature on three independent systems: (i) the pacemaker mechanism of the heart, (ii) the synthesis of sympathomimetic material, and (iii) the rate of inactivation of such material. In the summer heart (type C) synthesis is active and the material formed is protected by the relatively high level of circulating thyroid hormone. In the winter (type A) form, owing to the lower activity of the thyroid, the effects of inactivation lead to an exponential relation between pulse rate and frequency. Prior to the breeding season and in female frogs in the autumn there is apparently defective synthesis of adrenergic material and the type E relation appears. In January and February this type is often further modified, owing to thyroid inactivity, so that a constant acceleration is not maintained over the whole temperature range.

scholarly journals Estrogen mediates sex differences in preoptic neuropeptide and pituitary hormone production in medaka

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Junpei Yamashita ◽  
Yuji Nishiike ◽  
Thomas Fleming ◽  
Daichi Kayo ◽  
Kataaki Okubo
Keyword(s):  
Anterior Pituitary ◽  
Pituitary Hormones ◽  
Pituitary Hormone ◽  
Sexually Dimorphic ◽  
Hormone Production ◽  
Anterior Pituitary Hormones ◽  
Vertebrate Brain ◽  
Pituitary Adenylate Cyclase ◽  
Evolutionarily Conserved ◽  
Sexually Dimorphic Expression

AbstractThe preoptic area (POA) is one of the most evolutionarily conserved regions of the vertebrate brain and contains subsets of neuropeptide-expressing neurons. Here we found in the teleost medaka that two neuropeptides belonging to the secretin family, pituitary adenylate cyclase-activating polypeptide (Pacap) and vasoactive intestinal peptide (Vip), exhibit opposite patterns of sexually dimorphic expression in the same population of POA neurons that project to the anterior pituitary: Pacap is male-biased, whereas Vip is female-biased. Estrogen secreted by the ovary in adulthood was found to attenuate Pacap expression and, conversely, stimulate Vip expression in the female POA, thereby establishing and maintaining their opposite sexual dimorphism. Pituitary organ culture experiments demonstrated that both Pacap and Vip can markedly alter the expression of various anterior pituitary hormones. Collectively, these findings show that males and females use alternative preoptic neuropeptides to regulate anterior pituitary hormones as a result of their different estrogen milieu.

MRI analysis and surgical treatment of Wassel Type IV duplicated thumbs

2021 ◽  
pp. 175319342098321
Author(s):  
Anyuan Wang ◽  
Jian Ding ◽  
Long Wang ◽  
Tinggang Chu ◽  
Zhipeng Wu ◽  
...  
Keyword(s):  
Type A ◽  
Surgical Reconstruction ◽  
Mri Findings ◽  
Level Of Evidence ◽  
Type D ◽  
Type Iv ◽  
Secondary Operations ◽  
Type C

We present the MRI findings for 39 Wassel Type IV duplicated thumbs in 38 patients. We found that MRI revealed the morphology of the cartilaginous connection between the thumb anlages and the location of the deviation corresponding to the classification of Horii, which allowed precise preoperative planning of corrective osteotomies. All 39 thumbs were available for follow-up after surgical reconstruction at a mean of 29 months (range 25 to 39). Four out of nine Horii Type A cases and all 12 Type B, as well as the six Type C and the six Type D cases, achieved good results according to the Tada scoring system. Five Type A cases achieved fair results with residual stiffness of the interphalangeal joint. No secondary operations were needed. We conclude that MRI proved useful in subclassifying Wassel Type IV duplicated thumbs and may aid in planning the osteotomies needed for their reconstruction. Level of evidence: IV

scholarly journals THE HYPOPHYSIS AND SECRETION OF INSULIN

1942 ◽  
Vol 75 (5) ◽  
pp. 547-566 ◽  
Author(s):  
B. A. Houssay ◽  
V. G. Foglia ◽  
F. S. Smyth ◽  
C. T. Rietti ◽  
A. B. Houssay
Keyword(s):  
Insulin Secretion ◽  
B Cells ◽  
Blood Sugar ◽  
Anterior Pituitary ◽  
Blood Sugar Level ◽  
Pituitary Hormone ◽  
Pituitary Extract ◽  
Histological Changes ◽  
High Blood Sugar ◽  
Anterior Pituitary Hormone

The ability of the pancreas, from various types of dogs, to correct diabetic hyperglycemia has been studied (Table XI). The pancreas from one animal was united by a vascular union with the neck blood vessels of another dog which had been pancreatectomized for 20 hours. The time necessary to reduce the blood sugar level to 120 mg. per cent was determined. 1. Pancreas from 6 hypophysectomized dogs produced a normal insulin secretion, showing that an anterior pituitary hormone is not necessary for its production or maintenance. 2. In 14 of 17 normal dogs given anterior pituitary extract for 3 or more consecutive days and presenting diabetes (fasting blood sugar 150 mg. per cent or more) the pancreas showed diminished insulin production. 3. In animals which remained diabetic after discontinuing the injections of hypophyseal extract, the pancreas islands were markedly pathologic and the insulin secretion was practically nil. 4. When hyperglycemia existed on the 2nd to 5th day but fell later, the insulin secretion of 5 dogs was normal in 2, supernormal in 1, and less than normal in 2. Histologic examination showed a restoration of beta cells. 5. In 14 dogs resistant to the diabetogenic action of anterior pituitary extract, as shown by little or no change in blood sugar, the pancreatic secretion of insulin was normal in 6 cases, supernormal in 3, and subnormal in 5 cases. Clear signs of hyperfunction of B cells were observed. In 6 resistant animals a high blood sugar (150 mg. per cent) appeared shortly before transplanting, but insulin secretion was normal in 4, supernormal in 1, and subnormal in 1 case. 6. With one injection of extract and 1 day of hyperglycemia the capacity of the pancreas to secrete insulin was not altered. 7. A high blood sugar level lasting 4 days does not alter the islets. The hypophyseal extract acts, therefore, by some other mechanism. In normal dogs, the continuous intravenous infusion of glucose for 4 days maintained the blood sugar at levels as high as those after pituitary extract. In these animals the B cells were hyperplastic and insulin secretion normal. 8. Anterior hypophyseal hyperglycemia is due at first to extrapancreatic factors which are the most important, and last only during the injections of extracts. Pancreatic factors appear afterwards and are responsible for permanent diabetes. Hypophyseal extract produces histological changes in many tissues and damages the Langerhans islands. The coexistent high blood sugar probably exhausts the B cells and exaggerates their injury. 9. In all cases there is a relation between the cytology of the islet B cells and the insulin secreting capacity.

scholarly journals Paediatric Langerhans Cell Histiocytosis Disease: Long-Term Sequelae in the Hypothalamic Endocrine System

2021 ◽  
pp. 1-9
Author(s):  
Elisa Vaiani ◽  
Guido Felizzia ◽  
Fabiana Lubieniecki ◽  
Jorge Braier ◽  
Alicia Belgorosky
Keyword(s):  
Anterior Pituitary ◽  
Langerhans Cell Histiocytosis ◽  
Endocrine System ◽  
Langerhans Cell ◽  
Hormone Deficiency ◽  
Bone Lesions ◽  
Pituitary Hormone ◽  
Multisystem Disease ◽  
Anterior Pituitary Hormone

Langerhans cell histiocytosis (LCH) is a disorder of the mononuclear phagocyte system that can affect almost any organ and system. The most common central nervous system (CNS) manifestation in LCH is the infiltration of the hypothalamic-pituitary region leading to destruction and neurodegeneration of CNS tissue. The latter causes the most frequent endocrinological manifestation, that is, central diabetes insipidus (CDI), and less often anterior pituitary hormone deficiency (APD). The reported incidence of CDI is estimated between 11.5 and 24% and is considered a risk factor for neurodegenerative disease and APD. Three risk factors for development of CDI are recognized in the majority of the studies: (1) multisystem disease, (2) the occurrence of reactivations or active disease for a prolonged period, and (3) the presence of craniofacial bone lesions. Since CDI may occur as the first manifestation of LCH, differential diagnosis of malignant diseases like germ cell tumours must be made. APD is almost always associated with CDI and can appear several years after the diagnosis of CDI. Growth hormone is the most commonly affected anterior pituitary hormone. Despite significant advances in the knowledge of LCH in recent years, little progress has been made in preventing long-term sequelae such as those affecting the hypothalamic-pituitary system.

Anterior Pituitary Hormone Abnormalities following Traumatic Brain Injury

2005 ◽  
Vol 22 (9) ◽  
pp. 937-946 ◽  
Author(s):  
Manfred Schneider ◽  
Harald Jörn Schneider ◽  
Günter Karl Stalla
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Anterior Pituitary ◽  
Pituitary Hormone ◽  
Anterior Pituitary Hormone
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