Halperin R, Shinnar N, Kronfeld-Schor N, Hadas E. Effect of intrauterine injection of casein on fetal survival in rat: a new pharmacological approach for contraception.
Contraception 2006;
73:641-4. [PMID:
16730499 DOI:
10.1016/j.contraception.2005.11.002]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2005] [Revised: 11/04/2005] [Accepted: 11/14/2005] [Indexed: 11/18/2022]
Abstract
BACKGROUND
The incidental finding of casein as a possible new local pharmacological contraceptive prompted us to assess its validity in an experimental rat model.
METHODS
The intrauterine injection of 150 microg of bovine alpha-casein dissolved in 150 microL phosphate-buffered saline (PBS) was performed on one uterine rat horn on days L(5)-L(7), whereas the contralateral horn was used for injection of 150 microL PBS as a control. Intraperitoneal injection of alpha-casein (5 mg/mL, 2 mL/rat) was performed on day L(5). The rats were killed by cervical dislocation on the day L(14).
RESULTS
The effect of an alpha-casein on fetal resorption rate was assessed following the unilateral injection of 150 microL of alpha-casein (1 mg/mL in PBS) and compared with the effect obtained following the contralateral injection of 150 microL PBS. The unilateral injection of alpha-casein on day L(5) caused a significant increase in fetal resorption rate as compared with the contralateral uterine horn injected with PBS (p<.00001). The decrease in alpha-casein concentration from 1 to 0.3 mg/mL caused a reduced, but still significant, effect on fetal resorption rate (p<.0001). The injection on days L(6)-L(7) caused a local effect of resorption near the injection site. There was no effect on fetal resorption rate following the injection of alpha-casein intraperitoneally.
CONCLUSION
Our data suggest a new pharmacological approach for contraception, based on local intrauterine effect of alpha-casein in an experimental rat model. The exact mechanism of action related to casein should be further studied.
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