scholarly journals Toxic effects of carbendazim at low dose levels in male rats

2008 ◽  
Vol 33 (1) ◽  
pp. 25-30 ◽  
Author(s):  
V. Muthuviveganandavel ◽  
P. Muthuraman ◽  
S. Muthu ◽  
K. Srikumar
Keyword(s):  
Low Dose ◽  
Toxic Effects ◽  
Male Rats ◽  
Dose Levels

STUDIES ON ALDOSTERONE: III. CHRONIC EFFECT ON THE BLOOD PRESSURE OF RATS

1960 ◽  
Vol 38 (1) ◽  
pp. 43-50 ◽  
Author(s):  
A. G. Gornall ◽  
H. M. Grundy ◽  
C. J. Koladich
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Protective Effect ◽  
Systolic Blood Pressure ◽  
Low Dose ◽  
Aqueous Ethanol ◽  
Young Male ◽  
Male Rats ◽  
Chronic Effect ◽  
Dose Levels

A rise in systolic blood pressure due to the administration of 0.4 or 0.5 μg of aldosterone per 100 g body weight to young male rats, over a period of 3 to 6 months, has been confirmed in two separate experiments. This effect was observed whether the aldosterone was given 3 days a week or 6 days a week, and whether dissolved in aqueous ethanol or in oil. Equal doses of 9-α-fluorohydrocortisone and of 2-methyl-9-α-fluorohydrocortisone produced similar though somewhat less consistent effects. When 4 or 5 μg of reserpine was administered along with aldosterone there was no clear evidence of a protective effect. Reserpine alone at these low dose levels was somewhat toxic in the rat and led to a rise in blood pressure.

Honey attenuates the toxic effects of the low dose of tartrazine in male rats

2019 ◽  
Vol 43 (4) ◽  
pp. e12780 ◽  
Author(s):  
Haddad A. El Rabey ◽  
Madeha N. Al‐Seeni ◽  
Abdulbasit I. Al‐Sieni ◽  
Amani Mohammed Al‐Hamed ◽  
Mazin A. Zamzami ◽  
...  
Keyword(s):  
Low Dose ◽  
Toxic Effects ◽  
Male Rats

STUDIES ON ALDOSTERONE: III. CHRONIC EFFECT ON THE BLOOD PRESSURE OF RATS

1960 ◽  
Vol 38 (1) ◽  
pp. 43-50 ◽  
Author(s):  
A. G. Gornall ◽  
H. M. Grundy ◽  
C. J. Koladich
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Protective Effect ◽  
Systolic Blood Pressure ◽  
Low Dose ◽  
Aqueous Ethanol ◽  
Young Male ◽  
Male Rats ◽  
Chronic Effect ◽  
Dose Levels

A rise in systolic blood pressure due to the administration of 0.4 or 0.5 μg of aldosterone per 100 g body weight to young male rats, over a period of 3 to 6 months, has been confirmed in two separate experiments. This effect was observed whether the aldosterone was given 3 days a week or 6 days a week, and whether dissolved in aqueous ethanol or in oil. Equal doses of 9-α-fluorohydrocortisone and of 2-methyl-9-α-fluorohydrocortisone produced similar though somewhat less consistent effects. When 4 or 5 μg of reserpine was administered along with aldosterone there was no clear evidence of a protective effect. Reserpine alone at these low dose levels was somewhat toxic in the rat and led to a rise in blood pressure.

EFFECT OF OESTRONE-PELLET IMPLANTATION ON PLASMA LEVELS OF PROLACTIN

1970 ◽  
Vol 64 (2) ◽  
pp. 265-272 ◽  
Author(s):  
A. A. van der Gugten ◽  
M. Sala ◽  
H. G. Kwa
Keyword(s):  
Plasma Levels ◽  
Male Rats ◽  
Mean Values ◽  
The Mean ◽  
Dose Levels ◽  
Higher Doses ◽  
Primary Break

ABSTRACT Eight female and eight male rats were castrated at the age of 8 to 10 weeks. Four spayed and four orchidectomized rats received one oestrone/cholesterol pellet (200 μg oestrone) on the day of operation (day 0), a second pellet on day 11 and a third on day 23. The remaining animals received four oestrone/cholesterol pellets at these times. The fluctuations in the prolactin levels in the circulation induced by the oestrogen challenges in these animals were followed during 31 days by radioimmunoassays performed on days 3, 7, 9, 14, 15, 17, 23, 24, 25, 28 and 31. The results suggested that the homoeostatic mechanism regulating plasma levels of prolactin was capable of withstanding the three time-spaced oestrogen challenges only in the spayed animals receiving the lower doses of oestrogen, since it allowed the mean values of the prolactin levels to remain fairly constant during the first 4 weeks. The levels in this group rose to much higher levels only on day 31. The higher doses of oestrone in the spayed rats and both dose levels of oestrone in the orchidectomized animals apparently resulted in a primary break-down of the homoeostatic mechanism, since the prolactin levels in the animals of these groups rose to much higher levels either on day 7 or on day 9. This was followed by a period during which the prolactin levels appeared to be more or less under control, until a second and probably definitive failure of the homoeostatic mechanism allowed the mean levels to rise sharply again.

scholarly journals Vulnerability factors for mephedrone-induced conditioned place preference in rats—the impact of sex differences, social-conditioning and stress

2021 ◽  
Author(s):  
Olga Wronikowska ◽  
Maria Zykubek ◽  
Łukasz Kurach ◽  
Agnieszka Michalak ◽  
Anna Boguszewska-Czubara ◽  
...  
Keyword(s):  
Sex Differences ◽  
Conditioned Place Preference ◽  
Low Dose ◽  
Social Factor ◽  
Place Preference ◽  
Female Rats ◽  
Male Rats ◽  
Social Conditioning ◽  
Male And Female Rats ◽  
The Impact

Abstract Rationale Mephedrone is a frequently overused drug of abuse that belongs to the group of novel psychoactive substances. Although its mechanism of action, as well as toxic and psychoactive effects, has been widely studied, the role of different factors that could contribute to the increased vulnerability to mephedrone abuse is still poorly understood. Objectives The aim of the presented study was to assess the impact of several factors (sex differences, social-conditioning, and chronic mild unpredictable stress — CMUS) on the liability to mephedrone-induced reward in Wistar rats. Methods The rewarding effects of mephedrone in male and female rats were assessed using the conditioned place preference (CPP) procedure. Furthermore, the impact of social factor and stress was evaluated in male rats using social-CPP and CMUS-dependent CPP, respectively. Results Mephedrone induced classic-CPP in female (10 mg/kg), as well as in male (10 and 20 mg/kg) rats. However, the impact of mephedrone treatment during social-CPP was highly dose-dependent as the rewarding effects of low dose of mephedrone (5 mg/kg; non-active in classic-CPP) were potentiated when administered during social-conditioning. Interestingly, social-conditioning with a higher dose of 20 mg/kg (that induced classic-CPP) was able to reverse these effects. Finally, CMUS potentiated rewarding effects of a low dose of mephedrone (5 mg/kg) and increased the level of corticosterone in rats’ prefrontal cortex and hippocampus. Conclusions Altogether, the presented results give new insight into possible factors underlying the vulnerability to mephedrone abuse and can serve as a basis for further studies assessing mechanisms underlying observed effects.

Excitation of Putative Glutamatergic Neurons in the Rat Parabrachial Nucleus Region Reduces Delta Power during Dexmedetomidine but not Ketamine Anesthesia

2021 ◽  
Author(s):  
Eric D. Melonakos ◽  
Morgan J. Siegmann ◽  
Charles Rey ◽  
Christopher O’Brien ◽  
Ksenia K. Nikolaeva ◽  
...  
Keyword(s):  
Recovery Time ◽  
Low Dose ◽  
Designer Drugs ◽  
Male Rats ◽  
Parabrachial Nucleus ◽  
High Dose ◽  
Median Difference ◽  
Delta Power ◽  
Calcium Calmodulin Dependent ◽  
Ketamine Anesthesia

Background Parabrachial nucleus excitation reduces cortical delta oscillation (0.5 to 4 Hz) power and recovery time associated with anesthetics that enhance γ-aminobutyric acid type A receptor action. The effects of parabrachial nucleus excitation on anesthetics with other molecular targets, such as dexmedetomidine and ketamine, remain unknown. The hypothesis was that parabrachial nucleus excitation would cause arousal during dexmedetomidine and ketamine anesthesia. Methods Designer Receptors Exclusively Activated by Designer Drugs were used to excite calcium/calmodulin–dependent protein kinase 2α–positive neurons in the parabrachial nucleus region of adult male rats without anesthesia (nine rats), with dexmedetomidine (low dose: 0.3 µg · kg−1 · min−1 for 45 min, eight rats; high dose: 4.5 µg · kg−1 · min−1 for 10 min, seven rats), or with ketamine (low dose: 2 mg · kg−1 · min−1 for 30 min, seven rats; high dose: 4 mg · kg−1 · min−1 for 15 min, eight rats). For control experiments (same rats and treatments), the Designer Receptors Exclusively Activated by Designer Drugs were not excited. The electroencephalogram and anesthesia recovery times were recorded and analyzed. Results Parabrachial nucleus excitation reduced delta power in the prefrontal electroencephalogram with low-dose dexmedetomidine for the 150-min analyzed period, excepting two brief periods (peak median bootstrapped difference [clozapine-N-oxide – saline] during dexmedetomidine infusion = −6.06 [99% CI = −12.36 to −1.48] dB, P = 0.007). However, parabrachial nucleus excitation was less effective at reducing delta power with high-dose dexmedetomidine and low- and high-dose ketamine (peak median bootstrapped differences during high-dose [dexmedetomidine, ketamine] infusions = [−1.93, −0.87] dB, 99% CI = [−4.16 to −0.56, −1.62 to −0.18] dB, P = [0.006, 0.019]; low-dose ketamine had no statistically significant decreases during the infusion). Recovery time differences with parabrachial nucleus excitation were not statistically significant for dexmedetomidine (median difference for [low, high] dose = [1.63, 11.01] min, 95% CI = [−20.06 to 14.14, −20.84 to 23.67] min, P = [0.945, 0.297]) nor low-dose ketamine (median difference = 12.82 [95% CI: −3.20 to 39.58] min, P = 0.109) but were significantly longer for high-dose ketamine (median difference = 11.38 [95% CI: 1.81 to 24.67] min, P = 0.016). Conclusions These results suggest that the effectiveness of parabrachial nucleus excitation to change the neurophysiologic and behavioral effects of anesthesia depends on the anesthetic’s molecular target. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

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