| Abstrakt: |
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° 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 .01 μg of α-ergocryptine/mL of culture medium, .01 μg of ergonovine/mL of culture medium, .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 10-8Mconcentrations of perloline, N-formyl loline, N-acetyl loline, N-methyl loline, and α-ergocryptine. α-Ergocryptine suppressed (P< .10) prolactin secretion in both experiments. Ergonovine and perloline both stimulated (P< .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< .10) prolactin secretion. The endophyte-free seed extract treatment had no effect on prolactin secretion. In Exp. 2, prolactin secretion from AP responded to α-ergocryptine treatment in a dosedependent fashion.(ABSTRACT TRUNCATED AT 250 WORDS) |
