Testicular oxytocin: effects of intratesticular oxytocin in the rat

1991 ◽  
Vol 130 (2) ◽  
pp. 231-NP ◽  
Author(s):  
H. D. Nicholson ◽  
S. E. F. Guldenaar ◽  
G. J. Boer ◽  
B. T. Pickering
Keyword(s):  
Leydig Cells ◽  
Light And Electron Microscopy ◽  
Male Rats ◽  
Plasma Testosterone ◽  
Epididymal Sperm ◽  
Long Term Effects ◽  
Sperm Counts ◽  
Term Administration

ABSTRACT The long-term effects of oxytocin administration on the testis were studied using intratesticular implants. Adult male rats had an Accurel device containing 20 μg oxytocin (releasing approximately 200 ng/day) implanted into the parenchyma of each testis; control animals received empty devices. The animals were killed at weekly intervals for 4 weeks. Some animals were perfused and the testes processed for light and electron microscopy. Blood was collected from the remaining animals for the measurement of testosterone, dihydrotestosterone, LH, FSH and oxytocin; epididymal sperm counts were measured and the testes were extracted and radioimmunoassayed for testosterone, dihydrotestosterone and oxytocin. Long-term administration of oxytocin resulted in a significant reduction in testicular and plasma testosterone levels throughout the 4-week period examined and, after 14 days of treatment, lipid droplets were seen in the Leydig cells of treated but not control animals. Concentrations of dihydrotestosterone in the plasma and testes of the oxytocin-treated animals, however, were significantly elevated after 7 and 14 days and at no time fell below control values. Plasma FSH levels were also lower in the oxytocin-treated animals. Intratesticular oxytocin treatment did not affect LH or oxytocin concentrations in the plasma, epididymal sperm counts or the number of Leydig cells in the testis. Empty Accurel devices had no effect on testicular morphology. This study provides the first evidence that oxytocin in vivo can modify steroidogenesis in the testis. Journal of Endocrinology (1991) 130, 231–238

scholarly journals Effect of local heating of rat testes after suppression of spermatogenesis by pretreatment with a GnRH agonist and an anti-androgen

Reproduction ◽  
2002 ◽  
pp. 133-140 ◽  
Author(s):  
BP Setchell ◽  
L Ploen ◽  
EM Ritzen
Keyword(s):  
Cross Sections ◽  
Gnrh Agonist ◽  
Local Heating ◽  
Epididymal Sperm ◽  
Long Term Effects ◽  
Sperm Counts ◽  
Pachytene Spermatocytes ◽  
Tubular Diameter ◽  
Testis Mass

The effects of local heating of rat testes, in which spermatogenesis had been suppressed with injections of a GnRH agonist and an anti-androgen, were examined. Although the detrimental effects of heating were not as marked as those found in the testes of non-injected rats, the testes in which spermatogenesis was suppressed also showed a significant reduction in mass, the number of spermatozoa, tubular diameter and the percentage of normal tubular cross-sections at day 35 after heating. The results indicate that heating has an effect on cells in the testis other than those shown to be most susceptible to heat, namely pachytene spermatocytes and early spermatids, which were absent or markedly reduced in number when spermatogenesis was suppressed. The long-term effects of heating on the above parameters, as reported in a previous study, were also confirmed. However, in testes in which spermatogenesis was suppressed at the time of heating, there appeared to be no or a reduced long-term impairment of spermatogenesis, as determined by testis mass, the percentage of qualitatively normal tubules and epididymal sperm counts.

Effects of hypoxia on testosterone release in rat Leydig cells

2009 ◽  
Vol 297 (5) ◽  
pp. E1039-E1045 ◽  
Author(s):  
Guey-Shyang Hwang ◽  
Szu-Tah Chen ◽  
Te-Jung Chen ◽  
Shyi-Wu Wang
Keyword(s):  
Calcium Channel ◽  
Adenylyl Cyclase ◽  
Intermittent Hypoxia ◽  
Leydig Cells ◽  
Channel Blocker ◽  
Male Rats ◽  
Plasma Testosterone ◽  
Testosterone Production

The aim of this study was to explore the effect and action mechanisms of intermittent hypoxia on the production of testosterone both in vivo and in vitro. Male rats were housed in a hypoxic chamber (12% O2 + 88% N2, 1.5 l/ml) 8 h/day for 4 days. Normoxic rats were used as control. In an in vivo experiment, hypoxic and normoxic rats were euthanized and the blood samples collected. In the in vitro experiment, the enzymatically dispersed rat Leydig cells were prepared and challenged with forskolin (an adenylyl cyclase activator, 10−4 M), 8-Br-cAMP (a membrane-permeable analog of cAMP, 10−4 M), hCG (0.05 IU), the precursors of the biosynthesis testosterone, including 25-OH-C (10−5 M), pregnenolone (10−7 M), progesterone (10−7 M), 17-OH-progesterone (10−7 M), and androstendione (10−7-10−5 M), nifedipine (L-type Ca2+ channel blocker, 10−6-10−4 M), nimodipine (L-type Ca2+ channel blocker, 10−5 M), tetrandrine (L-type Ca2+ channel blocker, 10−5 M), and NAADP (calcium-signaling messenger causing release of calcium from intracellular stores, 10−6-10−4 M). The concentrations of testosterone in plasma and medium were measured by radioimmunoassay. The level of plasma testosterone in hypoxic rats was higher than that in normoxic rats. Enhanced testosterone production was observed in rat Leydig cells treated with hCG, 8-Br-cAMP, or forskolin in both normoxic and hypoxic conditions. Intermittent hypoxia resulted in a further increase of testosterone production in response to the testosterone precursors. The activity of 17β-hydroxysteroid dehydrogenase was stimulated by the treatment of intermittent hypoxia in vitro. The intermittent hypoxia-induced higher production of testosterone was accompanied with the influx of calcium via L-type calcium channel and the increase of intracellular calcium via the mechanism of calcium mobilization. These results suggested that the intermittent hypoxia stimulated the secretion of testosterone at least in part via stimulatory actions on the activities of adenylyl cyclase, cAMP, L-type calcium channel, and steroidogenic enzymes.

scholarly journals In vivo Activity of Dust Inhalation at Ratcon Quarry, Sokuro Village, Oluyole, Ibadan Oyo State

2021 ◽  
pp. 9-15
Author(s):  
Adeniyi Abayomi Olusegun
Keyword(s):  
Interstitial Pneumonia ◽  
Exposure Time ◽  
Male Rats ◽  
Human Beings ◽  
Long Term Effects ◽  
Air Concentration ◽  
Dust Inhalation ◽  
Average Body

A total of twenty (20) experimental adult male rats, aged 60 days (7 to 8 weeks) with average body weight between 150-200 gm were grouped, restrained inside laboratory approved plastic holders and exposed to dust inhalation at the quarry site with exposure time of 7, 14 and 21 days to reflect short-term effects while 42days represent long-term effects of dust inhalation on human beings. Each specimen was collected and sacrificed at their grouped survival periods and subjected to laboratory analysis that include Hematology and Histopathology of the lungs. The Hematologyresults of the 7 and 14days specimens revealed no remarkable changes in the Erythrogram (PCV, HB and RBC), the Leucogram (WBC) and the Platelets but however, the results of the 21 and 42 days specimen revealed leukocytosis (increase in WBC), lymphocytosis (increase Lym) and neutrophilia (increase neutrophils) (p<0.05). The Histopathology results of the first specimen (7 days exposure) showed no observable lesion, the second specimen(14 days) showed capillary congestion and mild interstitial pneumonia, while the third (21 days) and fourth (42 days) samples showed the rats graduating from mild to moderate interstitial pneumonia and oedema. The risk of these diseases depends on the amount of organic or inorganic dusts inhaled and deposited in the alveolar region, the air concentration of respirable dust as well as the exposure time and breathing pattern.

Differential effects of the administration of human chorionic gonadotropin to postnatal rats

1994 ◽  
Vol 142 (3) ◽  
pp. 527-534 ◽  
Author(s):  
F Gaytan ◽  
L Pinilla ◽  
J L Romero ◽  
E Aguilar
Keyword(s):  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Leydig Cells ◽  
Reproductive Function ◽  
Male Rats ◽  
Testicular Development ◽  
Long Term Effects ◽  
Adult Type ◽  
Short And Long Term

Abstract Neonatal and prepubertal male rats were treated with human chorionic gonadotropin (hCG, 5 IU/g body weight per day) on days 2–4 or 20–22. Depending on the date of treatment, different groups of rats were sacrificed at 5, 23, 30 and 100 days of age, in order to study the short-and long-term effects of the treatment with hCG on the development of the testes and sex accessory organs. Rats treated with hCG on days 2–4 showed increased number and size of foetal Leydig cells at 5 days of age. However, long-term effects include decreased numbers of adult-type Leydig cells, decreased weight of the testes and sex accessory organs, decreased basal and hCG-stimulated testosterone secretion, and delayed balano-preputial separation. In contrast, animals treated with hCG on days 20–22 showed similar short- and long-term effects, consisting of increased number of adult-type Leydig cells and macrophages, increased weight of the testes and sex accessory organs and advanced balano-preputial separation. In adulthood, both groups showed normal reproductive function. These results seem to indicate that the effects of hCG treatment in prepubertal rats are dependent on the type of Leydig cell stimulated, and suggest that foetal Leydig cells play a regulatory role in the early postnatal testicular development. Journal of Endocrinology (1994) 142, 527–534

Semen parameters, fertility and testosterone levels in male rats exposed prenatally to betamethasone

2009 ◽  
Vol 21 (5) ◽  
pp. 634 ◽  
Author(s):  
Renata C. Piffer ◽  
Patrícia C. Garcia ◽  
Daniela C. C. Gerardin ◽  
Wilma G. Kempinas ◽  
Oduvaldo C. M. Pereira
Keyword(s):  
Adult Male ◽  
Sperm Quality ◽  
Male Offspring ◽  
Male Rats ◽  
Semen Parameters ◽  
Plasma Testosterone ◽  
Control Group ◽  
Long Term Effects ◽  
Testosterone Levels

The present study investigated the long-term effects of prenatal betamethasone exposure on sperm quality and count, fertility and plasma testosterone levels in adult male rats. Pregnant rats received 0.1 mg kg–1 betamethasone on Days 12, 13, 18 and 19 of pregnancy. This treatment impaired sperm quality, sperm production, fertility and plasma testosterone levels in adult male offspring compared to the control group. Thus, the results of the present study indicate that the long-term effects of prenatal betamethasone exposure may be deleterious to offspring. The consequent decrease in testosterone production during adulthood, in association with damaged semen parameters, may explain for the observed decrease in the capacity of adult male offspring to themselves generate viable descendants.

Long-Term Effects of Panax Ginseng on Disposition of Fexofenadine in Rats in vivo

2009 ◽  
Vol 37 (04) ◽  
pp. 657-667 ◽  
Author(s):  
Ruhong Zhang ◽  
Jinjie Jie ◽  
Yan'an Zhou ◽  
Zhijian Cao ◽  
Wenxin Li
Keyword(s):  
Oral Dose ◽  
Panax Ginseng ◽  
Area Under The Curve ◽  
Pharmacokinetic Interaction ◽  
Male Rats ◽  
Pharmacokinetic Parameters ◽  
Sprague Dawley ◽  
Long Term Effects

This study was designed to explore the pharmacokinetic interaction of Panax Ginseng with fexofenadine in rats. Sprague-Dawley (SD) male rats were divided randomly into four groups: control oral and treatment oral dose groups ( n = 6, respectively); control intravenous and treatment intravenous dose groups ( n = 5, respectively). A single dose of fexofenadine (10 mg/kg for intravenous group rats and 100 mg/kg for oral dose group rats) was administered after 14 consecutive days of gastric gavage feeding of panax ginseng suspension (150 mg/kg/day) to treatment groups while the same volume of vehicle (1.6% ethanol) was administered as placebo to control groups. Blood samples were collected from 0 to 12 hours and levels of fexofenadine were measured by LC-MS/MS. Tissues were harvested to determine tissue/blood ratios. The pharmacokinetic parameters of fexofenadine were calculated using non-compartmental analysis. In the oral dose groups, (extravenous) panax ginseng decreased the area under the curve between 0–12 hours (AUC0–12) from 102490.7 ± 25273.5 to 49933.3 ± 12072.9 min*ng/ml ( p < 0.005), decreased C max from 1102.0 ± 116.6 to 274.3 ± 180.6 ng/ml ( p < 0.001), and significantly decreased ratios of brain to plasma concentration (B/P) ( p < 0.05). In the intravenous groups, panax ginseng only reduced B/P ratios ( p < 0.05). The mean bioavailability ( F ev ) of fexofenadine was decreased by 16.1% in the extravenous dose treatment group ( p < 0.05). Long term administration of panax ginseng to rats might induce both intestinal and brain endothelium p-glycoprotein (p-gp) expression. In addition, long term use of panax ginseng reduced the bioavailability of concurrently administered fexofenadine.

scholarly journals Long-term administration of vitamin A and the process of spermatogenesis

1999 ◽  
Vol 5 (1) ◽  
pp. 123-129
Keyword(s):  
Electron Microscopy ◽  
Retinoic Acid ◽  
Leydig Cells ◽  
Light And Electron Microscopy ◽  
Ultrastructural Changes ◽  
Retinol Acetate ◽  
Term Administration ◽  
Stopping Treatment ◽  
Prevention Of Cancer

The effect of retinoids on spermatogenesis in adult male gerbils [Gerbillus cheesemani]was studied using light and electron microscopy. Treatment with either 13-cis-retinoic acid or retinol acetate was given for 6 weeks and their effects were compared with controls. It was found that 13-cis-retinoic acid induced almost complete cessation of spermatogenesis and produced alterations in the cytoplasm of Leydig cells. No differences were seen in the testis of animals treated with retinol acetate compared with controls using light microscopy but it appeared to produce noticeable ultrastructural changes in Leydig cells. The changes observed were reversed 12 weeks after stopping treatment. Caution should be exercised regarding the use of dietary retinoids in the prevention of cancer

scholarly journals Long-term effects of carbon containing engineered nanomaterials and asbestos in the lung: one year postexposure comparisons

2014 ◽  
Vol 306 (2) ◽  
pp. L170-L182 ◽  
Author(s):  
Anna A. Shvedova ◽  
Naveena Yanamala ◽  
Elena R. Kisin ◽  
Alexey V. Tkach ◽  
Ashley R. Murray ◽  
...  
Keyword(s):  
Lung Tumor ◽  
Inhalation Exposure ◽  
Geometric Feature ◽  
Width Ratio ◽  
Long Term Effects ◽  
Genotoxic Effects ◽  
Pulmonary Exposure ◽  
Pharyngeal Aspiration

The hallmark geometric feature of single-walled carbon nanotubes (SWCNT) and carbon nanofibers (CNF), high length to width ratio, makes them similar to a hazardous agent, asbestos. Very limited data are available concerning long-term effects of pulmonary exposure to SWCNT or CNF. Here, we compared inflammatory, fibrogenic, and genotoxic effects of CNF, SWCNT, or asbestos in mice 1 yr after pharyngeal aspiration. In addition, we compared pulmonary responses to SWCNT by bolus dosing through pharyngeal aspiration and inhalation 5 h/day for 4 days, to evaluate the effect of dose rate. The aspiration studies showed that these particles can be visualized in the lung at 1 yr postexposure, whereas some translocate to lymphatics. All these particles induced chronic bronchopneumonia and lymphadenitis, accompanied by pulmonary fibrosis. CNF and asbestos were found to promote the greatest degree of inflammation, followed by SWCNT, whereas SWCNT were the most fibrogenic of these three particles. Furthermore, SWCNT induced cytogenetic alterations seen as micronuclei formation and nuclear protrusions in vivo. Importantly, inhalation exposure to SWCNT showed significantly greater inflammatory, fibrotic, and genotoxic effects than bolus pharyngeal aspiration. Finally, SWCNT and CNF, but not asbestos exposures, increased the incidence of K-ras oncogene mutations in the lung. No increased lung tumor incidence occurred after 1 yr postexposure to SWCNT, CNF, and asbestos. Overall, our data suggest that long-term pulmonary toxicity of SWCNT, CNF, and asbestos is defined, not only by their chemical composition, but also by the specific surface area and type of exposure.

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