Fifty reproductively mature female pinealectomized or sham-operated white-footed @entity19 (Peromyscus leucopus) were injected daily for 7 weeks with 50 micrograms @entity2493 at 12 hr after lights on. The injections started either on the day following surgery or 2 weeks after surgery. All @entity19 were maintained at room temperature under long-day photoperiod (LD 16:8). Pinealectomized and sham-operated @entity19 injected immediately following surgery and sham-operated @entity19 injected beginning 2 weeks after surgery had reduced reproductive tract weights (30 +/- 6, 33 +/- 6, and 33 +/- 3 mg, respectively) compared to the pinealectomized @entity19 injected beginning 2 weeks after surgery (78 +/- 8 mg). In a second study 74 pinealectomized or sham-operated @entity19 were injected at either 2, 7.5, 12, or 15 hr after lights on with 50 micrograms @entity2493 . Irrespective of surgical treatment, @entity19 injected at 15 hr had a mean (+/- SE) reproductive tract weight (33 +/- 10 mg) which was substantially less than the 2-hr group (78 +/- 17 mg) while the 7.5- and 12-hr groups were intermediate (P less than 0.001). Pinealectomized and sham-operated animals responded similarly to @entity2493 injections at these four time points (P less than 0.35). The clearance rate of plasma @entity2493 after a single 50-micrograms @entity2493 injection or after 2 weeks of daily injections at either 2 or 12 hr after lights on was determined. @entity2493 concentrations were determined using high-performance liquid chromatography and radioimmunoassay.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of timed XXXX injections on reproduction in pinealectomized Peromyscus leucopus.

@entity19 :: ('10090', 'Species') :: ['mice'] @entity2493 :: ('MESH:D008550', 'Chemical') :: ['melatonin', 'Melatonin']
@entity2493 :: (MESH:D008550,Chemical) :: ['melatonin']
