The effect of alkaloids and seed extracts of endophyte-infected tall fescue on prolactin secretion in an in vitro rat pituitary perfusion system

• Published in: Journal of animal science Vol. 70; no. 9; p. 2779
• Main Authors: Strickland, J.R. (Clemson University, Clemson, SC), Cross, D.L, Jenkins, T.C, Petroski, R.J, Powell, R.G
• Format: Journal Article
• Language: English
• Published: United States 01.09.1992
• Subjects: Acremonium - growth & development; ALCALOIDE; ALCALOIDES; Alkaloids - toxicity; Animals; DOSAGE BIOLOGIQUE; Dose-Response Relationship, Drug; ENDOFITAS; ENDOPHYTE; ENSAYO BIOLOGICO; Ergolines - toxicity; Ergonovine - toxicity; FESTUCA ARUNDINACEA; GLANDULA PITUITARIA; HORMONAS; HORMONE; HYPOPHYSE; Male; Organ Culture Techniques; Phenanthrenes; Pituitary Gland, Anterior - drug effects; Pituitary Gland, Anterior - metabolism; Plant Extracts - toxicity; Poaceae - microbiology; Prolactin - metabolism; PROLACTINA; PROLACTINE; Rats; Rats, Sprague-Dawley; SECRECION; SECRETION; Seeds; TECHNIQUE RADIOIMMUNOLOGIQUE; TECNICAS RADIOINMUNOLOGICAS
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/1992.7092779x

The objective of this research was to measure the effects of endophyte-infected tall fescue seed extract and various alkaloids associated with the endophyte on in vitro prolactin secretion by rat hemipituitaries. Rat anterior pituitaries (AP) were dissected into halves and placed in temperature-controlled culture chambers (37 degrees C). The tissue was perfused with culture media at a flow rate of 12 mL/h. After perfusion for at least 90 min with control media, AP halves were exposed to their respective treatments for 15 min before they were returned to the control media. The treatments for Exp. 1 were 0.01 micrograms of alpha-ergocryptine/mL of culture medium, 0.01 micrograms of ergonovine/mL of culture medium, 0.01 gram-equivalents of endophyte-infected tall fescue seed/mL of culture medium, and.01 gram-equivalents of endophyte free tall fescue seed/mL of culture medium. Treatments for Exp. 2 consisted of 10(-4), 10(-6), and 10(-8) M concentrations of perloline, N. formyl loline, N-acetyl loline, N-methyl loline, and alpha-ergocryptine. alpha-Ergocryptine suppressed (P 0.10) prolactin secretion in both experiments. Ergonovine and perloline both stimulated (P 0.10) prolactin secretion. The loline alkaloids (N-formyl loline, N-acetyl loline, N-methyl loline) had no effect on prolactin secretion. The endophyte-infected seed extract treatment suppressed (P 0.10) prolactin secretion. The endophyte-free seed extract treatment had no effect on prolactin secretion. In Exp. 2, prolactin secretion from AP responded to alpha-ergocryptine treatment in a dose-dependent fashion. Results indicate that this bioassay assay could be used to study adverse effects of the endophyte of tall fescue on prolactin release. Additionally, these data suggest that the ergopeptine group of alkaloids represented by alpha-ergocryptine may be causative agents for reduced serum prolactin levels in animals consuming endophyte-infected tall fescue