Catecholaminergic control of plasma growth hormone and thyrotropin levels in hypophysectomized rats bearing ectopic pituitary transplants

Esquifino, Ana I.; Agrasal, C.; Steger, Richard W.; Fernández‐Ruiz, Javier; Ramos, Jaime A.; Cebeira, M.; Bartke, Andrzej

doi:10.1016/0024-3205(87)90694-1

Cited by 6 publications

(2 citation statements)

References 19 publications

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“…An ectopic pituitary gland can release, besides prolactin [27], GH [28], TSH [29], gonadotropins [30] and ACTH [Esquifino, unpublished observa tions]; however, the circulating levels of these hormones did not change or even diminish in pituitary-grafted rats [25,30,31], Cyclosporine is a potent immunosuppres sive drug widely used to avert allograft rejec tion and in the therapy of autoimmune disor ders. The administration of cyclosporine in a rat cardiac allograft model in which prolactin levels were pharmacologically inhibited dou bled the graft survival time as compared to cyclosporine alone [17], This finding lends support to the hypothesis that cyclosporine has antagonistic effects with prolactin.…”

Section: Discussionmentioning

confidence: 99%

Age-Dependent Effect of Pituitary Transplants on Immune Responses in Rat Spleen: Modulatory Effect of Cyclosporine

Arce¹,

Castrillón²,

Cardinali³

et al. 1997

Neurosignals

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Male rats were grafted an anterior pituitary within breast muscles on day 5 or under the kidney capsule on day 30 or 60 of life. On the 70th day of life (rats operated on the 5th or 30th day) or on the 100th day of life (rats operated on the 60th day), rats were injected subcutaneously with Freund’s complete adjuvant, being killed 2 days later. Rats that had received a pituitary graft on the 30th day showed a greater degree of hyperprolactinemia than rats grafted on the 5th or 60th day. Analyzed as main factors in a factorial analysis of variance (ANOVA), pituitary transplants augmented splenic natural killer (NK) activity and lipopolysaccharide (LPS)- and concanavalin A (Con A)-induced cell proliferation, and decreased splenic cell number. As indicated by significant interactions between treatment and age of transplantation in a factorial ANOVA, splenic NK activity augmented in rats grafted on the 30th day of life, while LPS and Con A splenic cell proliferation augmented in rats grafted neonatally. Spleen cellularity decreased after pituitary transplants in 30- and 60-day-old rats. In a second study, the effect of cyclosporine on spleen immune responses was tested by administering cyclosporine (5 mg/kg) or vehicle to rats grafted as in experiment 1 for 5 days before sacrifice. Cyclosporine decreased splenic NK activity and LPS- and Con A-induced cell proliferation regardless of the presence of a pituitary graft. In rats grafted on the 30th day of life, cyclosporine reversed the effect of pituitary grafts on splenic NK activity, and ectopic pituitary augmenting NK activity in vehicle-treated rats while decreasing it in cyclosporine-injected rats. Cyclosporine reversed the inhibitory effect of pituitary transplants on spleen cell number. The high circulating prolactin levels found in rats with pituitary grafts were decreased by cyclosporine administration. The results are compatible with age-dependent promoting and inhibitory effects of hyperprolactinemia on the immune responses of the spleen, which were antagonized by cyclosporine immunosuppression.

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Section: Discussionmentioning

confidence: 99%

Age-Dependent Effect of Pituitary Transplants on Immune Responses in Rat Spleen: Modulatory Effect of Cyclosporine

Arce¹,

Castrillón²,

Cardinali³

et al. 1997

Neurosignals

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show abstract

“…In fact, an ectopic pituitary gland can release, besides prolactin [38], GH [39], TSH [39], gonadotropins [40] and ACTH [Esquifino, unpubl. observations].…”

Section: Discussionmentioning

confidence: 99%

Effect of Cyclosporine on Immune Responses in Submaxillary Lymph Nodes of Pituitary-Grafted Rats

Arce

Castrillón²,

Della‐Maggiore³

et al. 1996

Neurosignals

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This work was undertaken to analyze the interrelationships between prolactin and cyclosporine in affecting immune responsiveness in submaxillary lymph nodes. Male rats received an anterior pituitary graft within breast muscles on day 5, or under the kidney capsule, on day 30 or 60 of life. On day 70 (rats operated on day 5 or 30) or on day 100 (rats operated on day 60) animals were injected with Freund''s complete adjuvant and cyclosporine (5 mg/kg for 5 days), and were killed 2 days after immunization. Natural killer (NK) activity in submaxillary lymph node decreased in neonatally pituitary-grafted rats and increased in rats grafted on day 30 or 60, as did lymph node cellularity. Lipopolysaccharide (LPS)- and concanavalin A (ConA)-induced proliferation diminished in lymph nodes of rats grafted on day 30 or 60, respectively. Cyclosporine treatment diminished lymph node cell number and NK activity and increased the proliferative response to ConA. Cyclosporine depressive effect on lymph node cellularity was counteracted by the presence of a pituitary graft, as were the inhibition of NK activity and the stimulatory effect on ConA-induced cell proliferation. In pituitary-grafted rats, cyclosporine decreased submaxillary lymph node LPS-induced proliferation. Cyclosporine decreased the high circulating prolactin levels found in pituitary-grafted rats. The results are compatible with age-dependent, inhibitory and promoting activities of hyperprolactinemia on immune responses in lymph nodes, affected in a complex antagonistic and synergistic way by cyclosporine immunosuppression.

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Regulation of GH and TSH release from hyperplastic and ectopic pituitaries: Effects of dopamine in vitro

et al. 1989

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Catecholaminergic control of plasma growth hormone and thyrotropin levels in hypophysectomized rats bearing ectopic pituitary transplants

Cited by 6 publications

References 19 publications

Age-Dependent Effect of Pituitary Transplants on Immune Responses in Rat Spleen: Modulatory Effect of Cyclosporine

Age-Dependent Effect of Pituitary Transplants on Immune Responses in Rat Spleen: Modulatory Effect of Cyclosporine

Effect of Cyclosporine on Immune Responses in Submaxillary Lymph Nodes of Pituitary-Grafted Rats

Regulation of GH and TSH release from hyperplastic and ectopic pituitaries: Effects of dopamine in vitro

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