Hypothalamic, pituitary and gonadal hormone production in relation to nutrition in the male hyrax (Procavia capensis)

Millar, Robert P.; Fairall, N.

doi:10.1530/jrf.0.0470339

Cited by 4 publications

(2 citation statements)

References 11 publications

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“…The increases in plasma SBP which occur in little brown bats during the postnatal and postarousal periods occur at times of rapid increases in body weight (Damassa et ai, 1983 ;. Additionally, studies in other mammals have indicated that food availability can have profound effects on reproductive functions (Delost, 1975;Howland, 1975;Millar & Fairall, 1976;Berger, Negus, Sanders & Gardner, 1981;Kenagy & Bartholomew, 1981;Pirke & Spyra, 1981 ; Eskes, 1983;Nelson, Dark & Zucker, 1983;Barnes, 1984; for earlier references, see reviews by Leathern, 1970Leathern, , 1975. Nevertheless, the results of the present study indicate that the induction of SBP in the little brown bat is independent of changes in food intake or body mass.…”

Section: Discussionmentioning

confidence: 99%

Relationship of food intake to the induction of plasma sex steroid-binding protein and testicular activity in immature male little brown bats (Myotis lucifugus lucifugus)

Damassa¹,

Gustafson²

1985

Reproduction

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Immature male little brown bats were aroused prematurely from their first hibernation and fed ad libitum (Group AL) or given a restricted diet (Group FR). All animals were weighed daily and the food intake of Group FR males was restricted to maintain their body weights at or near initial post-arousal values (5.3-6.8 g). The average body weights of Group AL males increased during the first week after arousal and then stabilized at a level which was 20% higher than those of Group FR males. The post-arousal induction of plasma SBP was similar in Groups FR and AL: plasma SBP activity was significantly increased 1 week after arousal and by 3 weeks had reached levels which were more than 10-fold higher than those of immature hibernating males which served as controls. Although food restriction had no effect on plasma SBP levels, it did inhibit reproductive development. Arousal-induced increases in testicular and epididymal (head/body) weights in Group FR males were less than 50% of those in Group AL males. However, histological examination of the testes revealed similar degrees of spermatogenic activation in both groups. Plasma testosterone concentrations were increased markedly in Groups FR and AL; values were generally lower in Group FR but wide individual variations were observed. Despite these elevated peripheral testosterone values, the accessory sex glands in both groups remained unstimulated.

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Section: Discussionmentioning

confidence: 99%

Relationship of food intake to the induction of plasma sex steroid-binding protein and testicular activity in immature male little brown bats (Myotis lucifugus lucifugus)

Damassa¹,

Gustafson²

1985

Reproduction

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“…various small mammals indicate that inanition 265 may have consequences for the production and release of gonadotropin hormones (Howland and Skinner, 1973;Howland, 1975;Miller and Fairall, 1976). This paper describes two experiments.…”

Section: Introductionmentioning

confidence: 97%

Some effects of level of feeding and body condition upon sperm production and gonadotropin concentrations in the ram

Alkass¹,

Bryant²,

Walton

1982

Anim. Sci.

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1982). Some effects of level of feeding and body condition upon sperm production and gonadotropin concentrations in the ram. ABSTRACT 1. In two experiments. Scottish Blackface and Finnish Landrace cJ x Dorset Horn $ rams were housed in lightproof buildings and subjected to a constant 10-h light: 14-h dark photoperiod 70 days before and during the experiment. In experiment 1, four rams from each breed type were given either 750kJ/MJ(L) or 1250 to 1500 kJ/MJ(H) of their maintenance requirement for 20 weeks. In experiment 2, four rams of each breed were given either 750kJ/MJ(T) or 2000 kJ/MJ(F) of their maintenance requirement for 20 weeks, and were then fed to maintain live weight for a further 10 weeks. Daily sperm output in the urine and scrotal circumference were measured in both experiments. Various characteristics of ejaculated semen were measured in experiment 1. Sequential blood samples were collected from the rams on both experiments and assayed for follicle stimulating hormone and luteinizing hormone. At the end of each experiment the rams were slaughtered, and their testes, epididymides and anterior pituitary glands recovered.2. In Experiment 1, the L feeding level depressed progressively the numbers of sperm voided in the urine, scrotal circumference, and the concentration and total numbers of sperm in ejaculated semen. The testes and epididymides of L rams were lighter (/ > <001) and fewer sperm were recovered from the reproductive tract than in H rams (P<001). The pituitary glands were lighter (P<005) and contained less luteinizing hormone (/ ) <0-01) but amounts of follicle stimulating hormone similar to the H rams. Plasma luteinizing hormone levels were lower in L than in H rams at 20 weeks (/ > <005).3. In experiment 2, the T rams showed a progressive depression of numbers of sperm in the urine and scrotal circumference, such that at 20 weeks differences between F and T treatments were statistically significant (/ > <005 and 001 respectively). Subsequently, some recovery occurred which, with a reduction in these measures on F treatments, led to there being no statistically significant difference at 30 weeks. There were no statistically significant differences between F and T treatments in testes and epididymes weights, total number of sperm in the tract, and anterior pituitary weight, follicle stimulating hormone and luteinizing hormone content.

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Physiological responses of the adult male collared peccary, Tayassu tajacu (tayassuidae), to severe dietary restriction

Lochmiller

Hellgren

Varner

et al. 1985

Comparative Biochemistry and Physiology Part A: Physiology

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Hypothalamic, pituitary and gonadal hormone production in relation to nutrition in the male hyrax (Procavia capensis)

Cited by 4 publications

References 11 publications

Relationship of food intake to the induction of plasma sex steroid-binding protein and testicular activity in immature male little brown bats (Myotis lucifugus lucifugus)

Relationship of food intake to the induction of plasma sex steroid-binding protein and testicular activity in immature male little brown bats (Myotis lucifugus lucifugus)

Some effects of level of feeding and body condition upon sperm production and gonadotropin concentrations in the ram

Physiological responses of the adult male collared peccary, Tayassu tajacu (tayassuidae), to severe dietary restriction

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