CAP–cAMP increases the rate of formation of the closed promoter complex, CAP–cAMP provides CPC for conversion to the open promoter complex. 

Thus, the net effect of CAP–cAMP is to increase the rate of open promoter complex formation.

TLS Online TPP Program

#Id: 1226

#Unit 7. System Physiology – Animal

Vitamin D and PTH appear to stimulate production of mature osteoclasts through the dual action:

 1. Inhibiting OPG production

2. Stimulating RANKL formation

TLS Online TPP Program

#Id: 1227

#Unit 7. System Physiology – Animal

Glucocorticoids promote osteoclast activity and bone resorption by :

1. Increasing RANKL production 

2. Decreasing formation of OPG

TLS Online TPP Program

#Id: 1228

#Unit 7. System Physiology – Animal

Estrogen stimulates OPG production

TLS Online TPP Program

#Id: 1229

#Unit 7. System Physiology – Animal

PTH actions on the kidney:

1.  Inhibits phosphate reabsorption

2.  Stimulates Ca2+ reabsorption

TLS Online TPP Program

#Id: 1230

#Unit 7. System Physiology – Animal

PTH stimulates renal 1α-hydroxylase.

TLS Online TPP Program

#Id: 1231

#Unit 7. System Physiology – Animal

1α-hydroxylase, converts 25-hydroxycholecalciferol to the active form, 1,25-dihydroxycholecalciferol.