Mast cells. Mast cells and basophils are generally thought to be the major sources of histamine and can themselves be modulated by histamine as they express H 1, H 2 and H 4 receptors, although how this varies between different mast-cell types is not yet clear.
3. The pill is to be taken soon after unprotected sex. It should be taken preferably within 24 hours and before 72 hours or else the pill may turn useless. 4. I-pill checks pregnancy by preventing ovulation or fertilisation or implantation of the fertilised egg. 5. I-pill is 95 per cent effective if taken in time.
if you have already have sex your only option to avoid pregnancy after sex is to use the morning after pill which is referred to as emergency contraception you have to take it within 72 hours of sexual intercourse and you can get either by a prescription or directly from your doctor or health clinicf you have already have sex your only option to avoid pregnancy after sex is to use the morning after pill which is referred to as emergency contraception you have to take it within 72 hours of sexual intercourse and you can get either by a prescription or directly from your doctor or health clinic