SERUM 5α-ANDROSTANE-3α,17β-DIOL, ANDROSTERONE AND TESTOSTERONE CONCENTRATIONS IN THE IMMATURE MALE RAT: INFLUENCE OF TIME OF DAY

1977 ◽  
Vol 75 (1) ◽  
pp. 177-178 ◽  
Author(s):  
W. H. MOGER ◽  
P. R. MURPHY

Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4H7 (Received 22 April 1977) The concentration of testosterone in the serum of the adult rat varies significantly over a 24 h period (Kinson & Lui, 1973; Howland, 1975; Wilson, McMillan, Seal & Ahmed, 1976). However, studies on circadian variations in serum testosterone concentrations in immature male rats have yielded conflicting results. Grotjan & Johnson (1976) reported significant changes with time in 25–26-day-old Holtzman rats, whereas Döhler & Wuttke (1976) did not observe significant changes in 13–18 or 25–30-day-old Sprague–Dawley rats maintained on the same lighting schedule (14 h light: 10 h darkness). Recently we reported that from 20–35 days of age, 5α-androstane-3α,17β-diol (androstanediol) is the predominant androgen in the circulation of male rats (Moger, 1977). This study was undertaken to determine temporal variations in the concentrations of androstanediol, androsterone and testosterone. Forty-nine male Sprague

1967 ◽  
Vol 54 (3) ◽  
pp. 557-567 ◽  
Author(s):  
K.-O. Mosebach ◽  
H. Jühe ◽  
W. Dirscherl

ABSTRACT Over a period of 2 hours the distribution and the specific activities of 14C (dpm/mg C) in organs of immature male Sprague-Dawley rats were studied after infusion of testosterone-4-14C. Only in liver, adrenals, kidneys and lungs we found specific activities essentially higher than those of the blood. The values of testis, seminal vesicles, prostata, epididymis and penis were similar to blood. Corresponding to former experiments using injection technique the more physiological infusion technique did not show any accumulation of radioactivity in the target organs too. On the contrary the specific activity of the seminal vesicle secretion was clearly higher than those of the residue organ and the blood. In adrenals medulla contained more radioactivity than cortex, demonstrated by 3 different methods (combustion, extraction and histoautoradiography). The distributions of progesterone-4-14C and oestradiol-4-14C after infusion in immature male rats were similar to those of testosterone-4-14C. The latter did not show a striking affinity for uterus, vagina and ovaries after infusion into female immature rats.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
John C. Heath ◽  
Y. Abdelmageed ◽  
Tim D. Braden ◽  
Hari O. Goyal

Although male infertility is well researched, the effects of inorganic mercury on male reproduction and fertility are less well known. Studies pertaining to mercury and male fertility identified reduced concentration of testosterone in the serum of male workers, a toxic influence on fertility of organic mercury compounds within concentrations at the workplace, and increased days to pregnancy. We evaluated the effect of chronic mercuric chloride (HgCl2) exposure in male rats on reproductive endpoints. Thirty-day old male Sprague Dawley rats (n=31) were exposed to 0.0, 1.0, or 2.0 mg/kg/day of HgCl2via gavage. After 60 days exposure, they were housed with nonexposed females for 21 days. A survivor analysis revealed the exposed animals took longer to impregnate the females and had a lower rate of impregnation. Further statistical analysis revealed a lower correlation between testicular testosterone levels and days to impregnate, and also lower sperm counts in the epididymis head and body of the exposed males. The results indicate that HgCl2exposure had significant adverse effects on male rat reproduction endpoints including fertility at a dose that was not clinically toxic.


Author(s):  
Ronaldo Panggabean ◽  
Nofita ◽  
Ade Maria Ulfa

Basil leaf have antioxidants such as flavonoids, so it is thought to have a hepatoprotective effect. This study aims to investigate the effect of basil leaf extract on SGOT and SGPT levels in male rats induced by paracetamol. Basil leaf extract was carried out by the percolation method using ethyl acetate solvent, Some 20 male sprague dawley rats were randomly divided into 5 groups. Basil leaf extract (400 mg/kgBB and 600 mg/kgBB) and sylimarin (100 mg/kgBB) were carried out every day for 28 days, paracetamol was induced 24 hours after giving the last day of basil leaf extract. The parameters measured were SGOT and SGPT level to assess the effect of basil leaf extract on liver damage caused by paracetamol. The results showed that basil leaf extract (400 mg/kgBB dan 600 mg/kgBB) showed that the activities of SGOT and SGPT levels were statistically significant (p<0,05) to negative control. Basil leaf extract shows the effect of hepatoprotector on liver induced by paracetamol, however the effect given was not able to equate with positive control.


1977 ◽  
Vol 84 (2) ◽  
pp. 254-267 ◽  
Author(s):  
H. Edward Grotjan ◽  
Donald C. Johnson

ABSTRACT Follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone and androstenedione were measured by radioimmunoassays in the sera of immature male rats treated with luteinizing hormone-releasing hormone (LH-RH). A single dose of 10, 20, 40 or 80 ng of LH-RH produced a prompt increase in serum LH: significant changes in FSH were found only with the two larger doses. Serum testosterone increased to peak levels in 20 to 40 min and returned to control level by 120 min. Changes in androstenedione were temporally similar but smaller in magnitude. Four doses of 20 or 40 ng LH-RH given at 20 min intervals did not increase serum LH or testosterone concentrations above those found with a single injection; FSH was slightly higher after the fourth dose. However, 40 ng LH-RH given every 20 min for 2 h produced a dramatic increase in serum LH and FSH: serum and testicular androgens were also much higher during the second hour. A 2 h stimulation with 80 ng LH-RH given ip at 30 min intervals did not alter the response to the same treatment given 24 h later; i. e., neither the pituitary nor the gonad was primed by previous exposure to increased levels of LH-RH or gonadotrophins. These results suggest that a single pulse of LH-RH produces a predictable response in the animal, but multiple episodic stimuli produce variable responses: testes, on the other hand, produce androgens as long as gonadotrophins are available.


1987 ◽  
Vol 115 (4) ◽  
pp. 478-482 ◽  
Author(s):  
J. Roffi ◽  
F. Chami ◽  
P. Corbier ◽  
D. A. Edwards

Abstract. In the neonatal male rat, a rapid and transient increase in serum testosterone occurs about 2 h after birth. This post-partum testosterone surge (PPTS) has been implicated in the masculinization and defeminization of the central nervous system. The present study shows that environmental temperature can have a profound influence on the PPTS. Male rats were delivered from their mothers by caesarean section on day 22 of gestation. Immediately thereafter, neonatal males were placed at an ambient temperature of either 18, 21, 24 or 30°C. With 2 h of exposure, the body temperature was in close correspondence with the ambient temperature. The PPTS was clearly abolished in the pups exposed for 2 h at either 18 or 21°C. The effect of temperature was reversible: by placing pups at either 18 or 21°C for 2 h after delivery, and then rewarming by placing them with a foster mother, the PPTS was delayed until 4 h after birth, i.e. 2 h after the beginning of rewarming. Thus, environmental cooling appears to retard the development of neural and/or endocrine systems mediating the PPTS. Aberrant maternal care which would produce substantial cooling of the male pups would be expected to affect the PPTS, which in turn might affect the sexuality of male progeny.


2005 ◽  
Vol 24 (6) ◽  
pp. 451-467 ◽  
Author(s):  
Raymond G. York ◽  
John Barnett ◽  
Michael F. Girard ◽  
David R. Mattie ◽  
Marni V. K. Bekkedal ◽  
...  

A developmental neurotoxicity study was conducted to generate additional data on the potential functional and morphological hazard to the central nervous system caused by ammonium perchlorate in offspring from in utero and lactation exposure. Female Sprague-Dawley rats (23 to 25/group) were given continuous access to 0 (carrier), 0.1, 1.0, 3.0, and 10.0 mg/kg-day perchlorate in the drinking water beginning 2 weeks prior to mating and continuing through day 10 of lactation for the behavioral function assessment or given continuous access to 0 (carrier), 0.1, 1.0, 3.0, and 30.0 mg/kg-day beginning on gestation day 0 and continuing through day 10 of lactation for neurodevelopment assessments. Motor activity was conducted on postpartum days 14, 18, and 22 and juvenile brain weights, neurohistopathological examinations, and regional brain morphometry were conducted on postpartum days 10 and 22. This research revealed a sexually dimorphic response, with some brain regions being larger in perchlorate-treated male rats than in comparable controls. Even so, there was no evidence of any obvious exposure-related effects on male rat brain weights or neuropathology. The most consistent exposure-related effect in the male pups was on the thickness of the corpus callosum, with both the right- and left-sided measures of the thickness of this white matter tract being significantly greater for the male pups in the 0.1 and 1.0 mg/kg-day exposure groups. The behavioral testing suggests prenatal exposure to ammonium perchlorate does not affect the development of gross motor movements in the pups.


2021 ◽  
Vol 12 ◽  
Author(s):  
Christian Arias-Reyes ◽  
Sofien Laouafa ◽  
Natalia Zubieta-DeUrioste ◽  
Vincent Joseph ◽  
Aida Bairam ◽  
...  

Erythropoietin (EPO) regulates respiration under conditions of normoxia and hypoxia through interaction with the respiratory centers of the brainstem. Here we investigate the dose-dependent impact of EPO in the CB response to hypoxia and hypercapnia. We show, in isolated “en bloc” carotid body (CB) preparations containing the carotid sinus nerve (CSN) from adult male Sprague Dawley rats, that EPO acts as a stimulator of CSN activity in response to hypoxia at concentrations below 0.5 IU/ml. Under hypercapnic conditions, EPO did not influence the CSN response. EPO concentrations above 0.5 IU/ml decreased the response of the CSN to both hypoxia and hypercapnia, reaching complete inhibition at 2 IU/ml. The inhibitory action of high-dose EPO on the CSN activity might result from an increase in nitric oxide (NO) production. Accordingly, CB preparations were incubated with 2 IU/ml EPO and the unspecific NO synthase inhibitor (L-NAME), or the neuronal-specific NO synthase inhibitor (7NI). Both NO inhibitors fully restored the CSN activity in response to hypoxia and hypercapnia in presence of EPO. Our results show that EPO activates the CB response to hypoxia when its concentration does not exceed the threshold at which NO inhibitors masks EPO’s action.


2019 ◽  
Vol 26 (02) ◽  
Author(s):  
Sidra Hamid ◽  
Qaiser Aziz ◽  
Aneela Jamil ◽  
Lubna Meraj ◽  
Shazia Muazam ◽  
...  

Background: The most potent and effective drugs used for the management of blood pressure in hypertensive patients are Calcium channel blockers (CCBs). Nifedipine, a CCB, acts by blocking entry of calcium ions all the way through the voltage gated calcium channels (VGCCs) of L-type present in the smooth muscle cells of blood vesselsand reducing the blood pressure by decreasing the peripheral vascular resistance. Objectives: The study objective was to determine the effect of nifedipine on serum luteinizing hormone (LH) and serum testosterone in male Sprague Dawley rats. Study Design: Animal experimental study. Setting: All experiments were conducted at the Research laboratory of Shifa College of Medicine, Islamabad along with National Institute of Health (NIH), Islamabad. Period: October, 2012 to April, 2014. Methods: The study was done on adult male Sprague-Dawley rats (N= 60) aged 90-120 days old and their body weights varied between 200 + 50 grams. Rats were divided intotwo groups (n=30). Group A was administered0.5 ml distilled water/rat daily orally, group B was administered orally with nifedipine 50 mg/kg/rat dissolved in 1ml of DMSO. All the doses were given to rats for 8 weeks. After 8 weeks, serum luteinizing hormone and serum testosterone were measured in both groups. Results: In Nifedipine treated group, serum testosterone was significantly decreasedand serum LH was unaffected as compared to the control group. Conclusion: Nifedipine has adverse effects on male fertility as it decreases serum testosterone level.


1978 ◽  
Vol 79 (1) ◽  
pp. 85-89 ◽  
Author(s):  
J. A. M. MATTHEIJ ◽  
J. J. M. SWARTS

The occurrence of circadian variations in the concentration of prolactin in the plasma of 6- to 9-month-old male rats has been assessed in animals exposed to light for 14 h/day (lights on 06.00–20.00 h). Blood samples were obtained after decapitation, or from individual rats at regular intervals via a permanent cannula. Care was taken to limit stress during sampling. The concentration of prolactin in the plasma was significantly lower between 07.00 and 15.00 h than at other times. Between 15.00 and 20.00 h (during the light period), the concentration of prolactin was significantly higher in comparison with the preceding period, or with the remainder of the 24 h period. During the night, the concentration fluctuated, probably because of episodic releases of the hormone. The possible physiological significance of a circadian rhythm in the plasma concentration of prolactin and the implications for endocrine experimentation are discussed briefly.


1990 ◽  
Vol 122 (2) ◽  
pp. 168-174 ◽  
Author(s):  
Om P. Sharma ◽  
Shafiq A. Khan ◽  
Gerhard F. Weinbauer ◽  
Mohammed Arslan ◽  
Eberhard Nieschlag

Abstract The effects of androgens on the bioactivity and molecular composition of pituitary FSH were examined in intact and GnRH antagonist-suppressed male rats. Eight groups of adult Sprague-Dawley rats were subjected to the following treatments: antagonist (75 μg/day by osmotic minipumps; sc), testosterone-filled Silastic implants (3×5 cm, sc), dihydrotestosterone-filled Silastic implants (3×5 cm, sc), E2 benzoate (15 μg/day, sc), and combined administration of antagonist with either steroid for 3 weeks. At the end of the treatment period, pituitaries were dissected out and homogenised. FSH content was determined in the pituitary extracts by an in vitro bioassay and a radioimmunoassay. Individual pituitary extracts from rats treated with vehicle, testosterone and testosterone + antagonist were subjected to isoelectric-focusing on sucrose density gradients performed in the pH range from 3.5 to 7.0. Individual isoelectric-focusing fractions (100-120) were analysed for bioactive and immunoreactive FSH. Treatment with antagonist, E2 or antagonist + E2 caused a significant decrease in pituitary FSH, whereas testosterone and dihydrotesterone alone or in combination with antagonist prevented the decrease in pituitary FSH. The effects of all treatments on both bioactive and immunoreactive FSH were similar. Testosterone treatment not only maintained FSH synthesis but also altered the molecular composition of pituitary FSH. Following treatment with testosterone there was a shift of maximal FSH bioactivity to the more acidic pH range. On the other hand, less bioactivity was recovered than corresponding immunoreactivity in the higher pH region, resulting in significantly reduced ratios of bioactivity to immunoreactivity of FSH. No significant differences were found in the isoelectric-focusing profiles or bioactivity to immunoreactivity ratios of pituitary FSH in animals treated with testosterone alone or in combination with antagonist. The results demonstrate that testosterone not only maintained the synthesis of both bioactive and immunoreactive FSH in male rats, but also influences the molecular composition of pituitary FSH. These effects of testosterone on pituitary FSH appear not to be mediated through hypothalamic GnRH.


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