Meyer R L, Carlson K M, Rivier J, Wheaton J E
University of Minnesota, St. Paul 55108.
J Anim Sci. 1991 Feb;69(2):747-54. doi: 10.2527/1991.692747x.
A synthetic fragment representing the N-terminal 25 amino acid residues of the alpha-subunit of ovine inhibin (alpha-IF) was coupled to human alpha-globulin (h alpha-G) and used as an antigen. In Exp. 1, ovine antiserum generated against alpha-IF-h alpha-G was shown in vitro to neutralize inhibin bioactivity contained in ovine follicular fluid. In Exp. 2, 18 lambs were immunized with .3, .6 and 1.2 mg alpha-IF-h alpha-G or equivalent doses of h alpha-G. Antibody titer to alpha-IF was detected only in serum from lambs immunized against alpha-IF-h alpha-G and was first detected 27 +/- 2 d after primary immunization. Thereafter, antibody titers increased steadily. The degree of antibody responses was unrelated to antigen dose and differed among lambs. Plasma FSH concentrations were unchanged, whereas LH concentrations were lower (P less than .001) in sheep immunized against alpha-IF-h alpha-G. Ovulation rate was increased (3.5 +/- .5 vs 1.5 +/- .1; P less than .01) in lambs immunized against alpha-IF-h alpha-G. Ovulation rate was similar among animals receiving different antigen doses and increased with time after primary immunization (P less than .01). At estrous periods occurring approximately 34, 50, 74 and 107 d after primary immunization, respective ovulation rates were 157, 169, 207 and 450% of control values. Ovulation rate and antibody titer were correlated positively (pooled r = .95; P less than .01) within lambs. In Exp. 3, three lambs were immunized with .25 mg unconjugated alpha-IF; this was nonantigenic. In conclusion, the use of a synthetic fragment of the alpha-subunit of ovine inhibin as a hapten elicits an antibody capable of neutralizing inhibin bioactivity in vitro and increasing ovulation rate in vivo.
一个代表绵羊抑制素α亚基N端25个氨基酸残基的合成片段与人类α球蛋白（hα-G）偶联，并用作抗原。在实验1中，针对α-IF-hα-G产生的绵羊抗血清在体外显示可中和绵羊卵泡液中所含的抑制素生物活性。在实验2中，用0.3、0.6和1.2毫克α-IF-hα-G或等量剂量的hα-G对18只羔羊进行免疫。仅在针对α-IF-hα-G免疫的羔羊血清中检测到针对α-IF的抗体滴度，首次检测到是在初次免疫后27±2天。此后，抗体滴度稳步上升。抗体反应程度与抗原剂量无关，且在羔羊之间存在差异。在针对α-IF-hα-G免疫的绵羊中，血浆促卵泡素（FSH）浓度未改变，而促黄体素（LH）浓度较低（P<0.001）。针对α-IF-hα-G免疫的羔羊排卵率增加（3.5±0.5对1.5±0.1；P<0.01）。接受不同抗原剂量的动物之间排卵率相似，且在初次免疫后随时间增加（P<0.01）。在初次免疫后约34、50、74和107天出现发情期时，各自的排卵率分别为对照值的157%、169%、207%和450%。羔羊体内排卵率与抗体滴度呈正相关（合并r=0.95；P<0.01）。在实验3中，用0.25毫克未偶联的α-IF对3只羔羊进行免疫；这没有抗原性。总之，使用绵羊抑制素α亚基的合成片段作为半抗原来引发一种抗体，该抗体能够在体外中和抑制素生物活性并在体内提高排卵率。
