Summary and conclusionsTo assess the effects of oral contraceptives on anticoagulant treatment the prothrombin times of 12 patients were measured while they were taking both drugs simultaneously and while they were taking only anticoagulants. The mean prothrombin time ratio was significantly higher when patients were taking both drugs than when they were taking only anticoagulants and their doses of anticoagulant were significantly lower. During both periods most of the prothrombin values remained in the therapeutic range.These findings suggest that, contrary to the common belief that oral contraceptives diminish the effects of anticoagulants, contraceptives in fact potentiate the action of the anticoagulants. Patients and methodsAmong the 197 patients being followed in our anticoagulation control unit we found 12 women who were simultaneously taking an oral anticoagulant (nicoumalone) and an oestroprogestogenic oral contraceptive. In one case the contraceptive was a parenteral depot preparation, while the remaining 11 patients used oral preparations (see table). The patients were aged 27 to 44 years (mean 34-5), and none suffered from nephropathy, hepatopathy, or hypertensive disease.The indication for anticoagulation was the presence of a BjorkShiley valvular prosthesis in nine patients (five mitral, one aortic, three mitral and aortic), and the existence of embolic mitral valve disease in three patients.Anticoagulation control was carried out by measuring prothrombin activity according to Quick's method. Commercially obtained thromboplastin was used, but the reference values were from British comparative thromboplastin (BCT), and adequate correlations were established.2 The therapeutic range for commercial thromboplastin ranged generally from 1 3 to 1-8, corresponding to a prothrombin time ratio of 2 to 3 with BCT.The patients were followed for a total of 374 patient-months (mean

Os objetivos do presente trabalho foram: avaliar, na primavera e verão (novembro a março), a concentração plasmática de progesterona em ovelhas lanadas e deslanadas criadas no oeste paulista; avaliar a concentração plasmática de progesterona em função do tempo de permanência do progestágeno (6, 9 ou 12 dias) em protocolo de inseminação artificial em tempo fixo (IATF). No experimento 1 foram utilizadas 12 ovelhas mestiças: 6 padrão Texel (Te) e 6 Santa Inês (SI), nas quais foram feitas, entre novembro e março, sete colheitas de sangue (C1 a C7), por venopunção da jugular, para posterior dosagem de progesterona (P4)por radioimunoensaio (RIA). No experimento 2 foram utilizadas 38 ovelhas Te e SI divididas aleatoriamente em três grupos: G-6 (n= 13); G-9 (n= 13); e G-12 (n= 12). Inicialmente cada ovelha recebeu uma esponja intravaginal de progestágeno (D0) que permaneceu por 6 (G-6), 9 (G-9) ou 12 dias (G-12). Na retirada da esponja foram administrados, por via intramuscular, 0,1315 mg de prostaglandina F2α (PGF2α) e 300 UI de gonadotrofina coriônica equina (eCG). A IATF, por via laparoscópica, foi feita a partir de 50 horas após a retirada do progestágeno. Trinta dias após foi realizado diagnóstico de gestação através de ultrassonografia transabdominal. Exp. 1. Com exceção da colheita 7 (C7), em todas as outras o grupo SI apresentou concentração de P4 estatisticamente superior (P<0,05) ao grupo Te. Exp. 2. No momento da retirada do progestágeno o G-12 apresentou concentração de P4 significativamente (P<0,05)menor (0,342 ng/mL) que o G-6 (1,684 ng/mL) e G-9 (1,762 ng/mL). No entanto não houve diferença na taxa de prenhez entre os grupos G-6 (76,9%), G-9 (61,5%) e G-12 (91,6%). As ovelhas SI apresentaram concentração plasmática de P4 maior que as ovelhas Te nos períodos avaliados. A duração da permanência do progestágeno não afeta a taxa de prenhez em ovelhas.