Kits
FT3 ELISA
Kits
Description
The thyroid hormone, triiodothyronine (T3), is
produced by the thyroid gland. An important
component in the synthesis is iodine. Thyroxine is
converted to the active T3 (three to four times more
potent than T4) within cells by deiodinases (5'-
iodinase).
Thyroxine-binding globulin (TGB) is the major carrier
protein for circulating thyroid hormone.
Only a very small fraction of the circulating hormone is
free (unbound) 0.3%; this fraction is biologically active.
Thus, measurements of free triiodothyronine
concentrations correlate more reliably with clinical
status than total triiodothyronine levels. For example,
the increase in total triiodothyronine levels associated
with pregnancy, oral contraceptives and oestrogen
therapy result in higher total T3 levels while the free
T3 (FT3) concentration remains basically unchanged.
The concentrations of the carrier proteins are altered
in many clinical conditions, such as pregnancy. In
normal thyroid function as the concentrations of the
carrier proteins alters, the total triiodothyronine level
changes so that the free triiodothyronine concentration
remains constant.
The binding of T3 plays a key role in the feedback
control of the thyroid, with FT3 acting on the pituitary
to inhibit thyroid hormone secretion.
The thyronines act on the body to increase the basal
metabolic rate, affect protein synthesis and increase
the body's sensitivity to catecholamine (such as
adrenaline) by permissiveness. The thyroid hormones
are essential to proper development and differentiation
of all cells of the human body. These hormones also
regulate protein, fat, and carbohydrate metabolism,
affecting how human cells use energetic compounds.
Numerous physiological and pathological stimuli
influence thyroid hormone synthesis.
Thyrotoxicosis or hyperthyroidism is the clinical
syndrome caused by an excess of circulating free
thyroxine, free triiodothyronine, or both.
Both T3 and T4 are used to treat thyroid hormone
deficiency (hypothyroidism).
Since conditions such as pregnancy, oestrogen
therapy and other non-thyroid factors alter TBG
concentrations, assessment of thyroid function
through total T3 measurement may result in an
erroneous diagnosis, because FT3 levels, are
unaffected by binding protein changes.
produced by the thyroid gland. An important
component in the synthesis is iodine. Thyroxine is
converted to the active T3 (three to four times more
potent than T4) within cells by deiodinases (5'-
iodinase).
Thyroxine-binding globulin (TGB) is the major carrier
protein for circulating thyroid hormone.
Only a very small fraction of the circulating hormone is
free (unbound) 0.3%; this fraction is biologically active.
Thus, measurements of free triiodothyronine
concentrations correlate more reliably with clinical
status than total triiodothyronine levels. For example,
the increase in total triiodothyronine levels associated
with pregnancy, oral contraceptives and oestrogen
therapy result in higher total T3 levels while the free
T3 (FT3) concentration remains basically unchanged.
The concentrations of the carrier proteins are altered
in many clinical conditions, such as pregnancy. In
normal thyroid function as the concentrations of the
carrier proteins alters, the total triiodothyronine level
changes so that the free triiodothyronine concentration
remains constant.
The binding of T3 plays a key role in the feedback
control of the thyroid, with FT3 acting on the pituitary
to inhibit thyroid hormone secretion.
The thyronines act on the body to increase the basal
metabolic rate, affect protein synthesis and increase
the body's sensitivity to catecholamine (such as
adrenaline) by permissiveness. The thyroid hormones
are essential to proper development and differentiation
of all cells of the human body. These hormones also
regulate protein, fat, and carbohydrate metabolism,
affecting how human cells use energetic compounds.
Numerous physiological and pathological stimuli
influence thyroid hormone synthesis.
Thyrotoxicosis or hyperthyroidism is the clinical
syndrome caused by an excess of circulating free
thyroxine, free triiodothyronine, or both.
Both T3 and T4 are used to treat thyroid hormone
deficiency (hypothyroidism).
Since conditions such as pregnancy, oestrogen
therapy and other non-thyroid factors alter TBG
concentrations, assessment of thyroid function
through total T3 measurement may result in an
erroneous diagnosis, because FT3 levels, are
unaffected by binding protein changes.