The Effects of External Temperatures on a Rat's Metabolism

While the term "rat" is often used generally, there are in fact many species of rats found all over the world. Each of these has its own metabolic rate, and its own unique responses to temperature and temperature changes. However, when it comes to the effects of external temperatures on metabolism, each species of rat, like other rodents, follows the same pattern.

  1. Metabolism

    • Metabolism is the rate of activity in an organism. An organism's metabolism, or metabolic rate, is the sum total of all the processes in its body, both physical (heartbeat, for example) and chemical. Metabolism includes the processing of fuel, making of waste, and creation and consumption of energy.

    Oxygen Use

    • Metabolic activity, or metabolism, can be measured by looking at an organism's rate of oxygen consumption. The higher the rate of oxygen consumption, the higher the organism's current metabolic rate.

    Cool Temperatures

    • When the external temperature is cooler (lower), a rat's metabolism increases. The rat then consumes oxygen at a higher rate, generating more heat internally to maintain body temperature. The definition of a "cool" temperature varies by species of rat, however. For example, for the Egyptian roof rat (Rattus rattus), cool temperatures are those below thirty degrees Celsius. This midpoint, and the temperatures immediately surrounding it, is the species' zone of thermal neutrality and basal metabolism.

    Warm Temperatures

    • For temperatures above a rat species' zone of thermal neutrality and basal metabolism, metabolism gradually increases again as the temperature becomes warmer. At these warmer temperatures, oxygen usage again increases and metabolism goes up as the rat strives to keep its body temperature down.