Question

Which of the following two hormones have antagonistic effects?

• A. Parathormone and calcitonin
• B. FSH and LH
• C. Oestrogen and progesterone
• D. ADH and melatonin

Answer 1

The correct option is A Parathormone and calcitonin

When blood calcium levels drop, the parathyroid gland secretes a parathyroid hormone which increases the blood calcium levels by stimulating osteoclasts to break down bone and release calcium into the bloodstream.

But calcitonin, which is produced by the thyroid gland, lowers blood calcium levels. It counters the actions of parathyroid hormone which inhibits osteoclast function, slowing the breakdown of bone. By opposing the action of parathyroid hormone on the kidneys, it increases excretion of calcium in the urine.

So, the correct answer is option A.