Daily variations in the responses to papaverine but not theophylline in rat aorta

Uluoglu C., Hodoglugil U., Guney H., Gorgun C., Abacioglu N., Zengil H.

BIOLOGICAL RHYTHM RESEARCH, cilt.29, sa.4, ss.343-352, 1998 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 29 Sayı: 4
  • Basım Tarihi: 1998
  • Doi Numarası: 10.1076/brhm.29.4.343.1428
  • Dergi Adı: BIOLOGICAL RHYTHM RESEARCH
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.343-352
  • Gazi Üniversitesi Adresli: Hayır

Özet

The presence of temporal patterns in the responses of vascular smooth muscle to relaxing agents have been known. The aim of this study was to examine the variations in the in vitro sensitivity of rat aorta to papaverine and theophylline in both endothelium-intact and -denuded rings. The animals were synchronized with a 12-h light: 12-h dark schedule. Rat thoracic aorta rings were obtained from animals sacrificed at six different times (09:00, 13:00, 17:00, 21:00, 01:00 and 05:00) of the day. Tissues were precontracted submaximally with phenylephrine and then were relaxed by papaverine (10(-8)-10(-4) M) and theophylline (10(-7)-10(-3) M) applied cumulatively. The responses to most of the concentrations and EC50 values for papaverine demonstrated an ultradian rhythm with an 8 h periodicity. Time-dependent variations were not found in the responses to theophylline. The results are dis cussed in relation with the time-dependent differences in signal transducing mechanisms.