24-hour changes in circulating prolactin, follicle-stimulating hormone, luteinizing hormone and testosterone in male rats subjected to social isolation

Abstract

Background: This work analyzes the effect of social isolation (a mild stressor) on the 24-h variation of pituitary-testicular function in young Wistar rats, assessed by measuring circulating levels of prolactin, FSH, LH and testosterone.

Neuroendocrine-immune correlates of circadian physiology: studies in experimental models of arthritis, ethanol feeding, aging, social isolation, and calorie restriction

“…Isolation brought about a decrease in prolactin, LH and testosterone secretion and an increase of FSH secretion. In isolated rats the 24-h secretory pattern of prolactin and testosterone became modified, i.e., the maximum in prolactin seen in control animals at the beginning of the activity span was not longer detected while the maximum in circulating testosterone taking place at 17:00 h in controls was phase-delayed to 21:00 h in isolated rats [177].…”

“…To examine whether social isolation in growing male rats affected 24-h variations of activity of the hypophyseal gonadal axis the circadian pattern of plasma prolactin, LH, FSH, and testosterone levels at six different time points within a 24-h cycle in growing male rats kept in isolation or group-caged for 30 days [177]. Isolation brought about a decrease in prolactin, LH and testosterone secretion and an increase of FSH secretion.…”

Effect of social isolation on 24-h pattern of stress hormones and leptin in rats

“…It is notable, however, that regardless of the stress produced, social isolated male hamsters (Matt et al, 1983) or rats (Esquifino et al, 2004) exhibited a decrease in plasma prolactin, a hormone whose release is triggered by stress. Moreover, in other studies, individual housing of male mice decreased plasma glucocorticoid levels and adrenaline turnover in the adrenal glands, these hormonal changes again being indicative of a decreased stress (Brain, 1975;Sayegh et al, 1990).…”

Fecal Concentrations of Cortisol, Testosterone, and Progesterone in Cotton-Top Tamarins Housed in Different Zoological Parks: Relationships Among Physiological Data, Environmental Conditions, and Behavioral Patterns

“…Previous research demonstrated that social isolation modifies testosterone basal concentrations in rodents (Sachser, 1986;Sayegh, Kobor, Lajtha, & Vadasz, 1990). However, the results are contradictory; in rats, for example, Fulgheri, Di Prisco, & Verdarelli (1975) and Gamallo, Villanua, Trancho, & Fraile (1986) observed an enhancement of endocrine responses, whereas Esquifino, Chacon, Jimenez, Reyes Toso, & Cardinali (2004) and Sanchez, Aguado, Sanchez-Toscano, & Saphier, (1995) reported its suppression. Group composition and exhibit type also affect fecal progesterone concentrations, but in this case we suggest that the cyclic activity of the animal may influence this effect.…”