Which of the following hormones is released by pancreas and regulate body metabolic pathway?

Insulin

The correct answer is option 4. Insulin.

The hormone released by the pancreas that regulates body metabolic pathways is Insulin.

Source: Produced and released by the beta cells of the pancreas.

Function: Regulates glucose metabolism by promoting the uptake of glucose into cells, thereby lowering blood glucose levels. It also influences the storage of glucose as glycogen in the liver and muscle and affects lipid and protein metabolism.

Other Hormones:

1. Melatonin:

Source: Produced by the pineal gland.

Function: Regulates sleep-wake cycles and seasonal biological rhythms. It is not involved in direct regulation of metabolic pathways.

2. Estrogen:

Source: Produced primarily by the ovaries (and in smaller amounts by other tissues).

Function: Involved in the regulation of the reproductive system and secondary sexual characteristics. It has some influence on metabolism but is not primarily involved in metabolic regulation.

3. Adrenaline (Epinephrine):

Source: Produced by the adrenal glands.

Function: Increases heart rate, dilates airways, and prepares the body for a "fight or flight" response. It has effects on glucose metabolism but is not specifically a metabolic regulatory hormone.

Therefore, Insulin is the hormone specifically released by the pancreas to regulate body metabolic pathways.